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Search for "organometallic nucleophiles" in Full Text gives 12 result(s) in Beilstein Journal of Organic Chemistry.
Pauson–Khand reaction of fluorinated compounds
- Jorge Escorihuela,
- Daniel M. Sedgwick,
- Alberto Llobat,
- Mercedes Medio-Simón,
- Pablo Barrio and
- Santos Fustero
Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138
- this sense, while the addition of hard organometallic nucleophiles, such as lithium dialkylcuprates or Grignard reagents, failed, softer nucleophiles such as nitroalkanes cleanly added to the β-position, providing the Michael adduct 61. Unexpectedly, the conjugate addition reaction resulted in
Graphical Abstract
Scheme 1: Schematic representation of the Pauson–Khand reaction.
Scheme 2: Substrates included in this review.
Scheme 3: Commonly accepted mechanism for the Pauson–Khand reaction.
Scheme 4: Regioselectivity of the PKR.
Scheme 5: Variability at the acetylenic and olefinic counterpart.
Scheme 6: Pauson–Khand reaction of fluoroolefinic enynes reported by the group of Ishizaki [46].
Scheme 7: PKR of enynes bearing fluorinated groups on the alkynyl moiety, reported by the group of Ishizaki [46]....
Scheme 8: Intramolecular PKR of 1,7-enynes reported by the group of Billard [47].
Scheme 9: Intramolecular PKR of 1,7-enynes reported by the group of Billard [48].
Scheme 10: Intramolecular PKR of 1,7-enynes by the group of Bonnet-Delpon [49]. Reaction conditions: i) Co(CO)8 (1...
Scheme 11: Intramolecular PKR of 1,6-enynes reported by the group of Ichikawa [50].
Scheme 12: Intramolecular Rh(I)-catalyzed PKR reported by the group of Hammond [52].
Scheme 13: Intramolecular PKR of allenynes reported by the group of Osipov [53].
Scheme 14: Intramolecular PKR of 1,7-enynes reported by the group of Osipov [53].
Scheme 15: Intramolecular PKR of fluorine-containing 1,6-enynes reported by the Konno group [54].
Scheme 16: Diastereoselective PKR with enantioenriched fluorinated enynes 34 [55].
Scheme 17: Intramolecular PKR reported by the group of Martinez-Solorio [56].
Scheme 18: Fluorine substitution at the olefinic counterpart.
Scheme 19: Synthesis of fluorinated enynes 37 [59].
Scheme 20: Fluorine-containing substrates in PKR [59].
Scheme 21: Pauson Khand reaction for fluorinated enynes by the Fustero group: scope and limitations [59].
Scheme 22: Synthesis of chloro and bromo analogues [59].
Scheme 23: Dimerization pathway [59].
Scheme 24: Synthesis of fluorine-containing N-tethered 1,7-enynes [61].
Scheme 25: Intramolecular PKR of chiral N-tethered fluorinated 1,7-enynes [61].
Scheme 26: Examples of further modifications to the Pauson−Khand adducts [61].
Scheme 27: Asymmetric synthesis the fluorinated enynes 53.
Scheme 28: Intramolecular PKR of chiral N-tethered 1,7-enynes 53 [64].
Scheme 29: Intramolecular PKR of chiral N-tethered 1,7-enyne bearing a vinyl fluoride [64].
Scheme 30: Catalytic intramolecular PKR of chiral N-tethered 1,7-enynes [64].
Scheme 31: Model fluorinated alkynes used by Riera and Fustero [70].
Scheme 32: PKR with norbornadiene and fluorinated alkynes 58 [71].
Scheme 33: Nucleophilic addition/detrifluoromethylation and retro Diels-Alder reactions [70].
Scheme 34: Tentative mechanism for the nucleophilic addition/retro-aldol reaction sequence.
Scheme 35: Catalytic PKR with norbornadiene [70].
Scheme 36: Scope of the PKR of trifluoromethylalkynes with norbornadiene [72].
Scheme 37: DBU-mediated detrifluoromethylation [72].
Scheme 38: A simple route to enone 67, a common intermediate in the total synthesis of α-cuparenone.
Scheme 39: Effect of the olefin partner in the regioselectivity of the PKR with trifluoromethyl alkynes [79].
Scheme 40: Intermolecular PKR of trifluoromethylalkynes with 2-norbornene reported by the group of Konno [54].
Scheme 41: Intermolecular PKR of diarylalkynes with 2-norbornene reported by the group of Helaja [80].
Scheme 42: Intermolecular PKR reported by León and Fernández [81].
Scheme 43: PKR reported with cyclopropene 73 [82].
Architecture and synthesis of P,N-heterocyclic phosphine ligands
- Wisdom A. Munzeiwa,
- Bernard Omondi and
- Vincent O. Nyamori
Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35
- from α-C–H bond activation in heterocycles The α-position to a heteroatom in a cyclic compound is activated because of the difference in electronegativity with carbon. This presents an opportunity to readily generate organometallic nucleophiles. Chelucci et al. [71] used this fact to synthesize the
Graphical Abstract
Scheme 1: Synthesis of pyridylphosphine ligands.
Figure 1: Pyridylphosphine ligands.
Scheme 2: Synthesis of piperidyl- and oxazinylphosphine ligands.
Scheme 3: Synthesis of linear multi-chelate pyridylphosphine ligands.
Scheme 4: Synthesis of chiral acetal pyridylphosphine ligands.
Scheme 5: Synthesis of diphenylphosphine-substituted triazine ligands.
Scheme 6: Synthesis of (pyridine-2-ylmethyl)phosphine ligands.
Scheme 7: Synthesis of diphosphine pyrrole ligands.
Scheme 8: Synthesis of 4,5-diazafluorenylphosphine ligands.
Scheme 9: Synthesis of thioether-containing pyridyldiphosphine ligands starting from ethylene sulfide and dip...
Scheme 10: Synthesis of monoterpene-derived phosphine pyridine ligands.
Scheme 11: Synthesis of N-phenylphosphine-substituted imidazole ligands.
Scheme 12: Synthesis of triazol-4-ylphosphine ligands.
Scheme 13: Synthesis of phosphanyltriazolopyridines and product selectivity depending on the substituents’ eff...
Scheme 14: Synthesis of PTA-phosphine ligands.
Scheme 15: Synthesis of isomeric phosphine dipyrazole ligands by varying the reaction temperature.
Scheme 16: Synthesis of N-tethered phosphine imidazolium ligands (route A) and diphosphine imidazolium ligands...
Scheme 17: Synthesis of {1-[2-(pyridin-2-yl)- (R = CH) and {1-[2-(pyrazin-2-yl)quinazolin-4-yl]naphthalen-2-yl...
Scheme 18: Synthesis of oxazolylindolylphosphine ligands 102.
Scheme 19: Synthesis of pyrrolylphosphine ligands.
Scheme 20: Synthesis of phosphine guanidinium ligands.
Scheme 21: Synthesis of a polydentate aminophosphine ligand.
Scheme 22: Synthesis of quinolylphosphine ligands.
Scheme 23: Synthesis of N-(triazolylmethyl)phosphanamine ligands.
Figure 2: Triazolylphosphanamine ligands synthesized by Wassenaar’s method [22].
Scheme 24: Synthesis of oxazaphosphorines.
Scheme 25: Synthesis of paracyclophane pyridylphosphine ligands.
Scheme 26: Synthesis of triazolylphosphine ligands.
Figure 3: Click-phosphine ligands.
Scheme 27: Ferrocenyl pyridylphosphine imine ligands.
Scheme 28: Synthesis of phosphinooxazolines (PHOX).
Scheme 29: Synthesis of ferrocenylphosphine oxazoles.
Copper-catalyzed enantioselective conjugate addition of organometallic reagents to challenging Michael acceptors
- Delphine Pichon,
- Jennifer Morvan,
- Christophe Crévisy and
- Marc Mauduit
Beilstein J. Org. Chem. 2020, 16, 212–232, doi:10.3762/bjoc.16.24
- Delphine Pichon Jennifer Morvan Christophe Crevisy Marc Mauduit Université de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR – UMR 6226, F-35000 Rennes, France 10.3762/bjoc.16.24 Abstract The copper-catalyzed enantioselective conjugate addition (ECA) of organometallic
- nucleophiles to electron-deficient alkenes (Michael acceptors) represents an efficient and attractive methodology for providing a wide range of relevant chiral molecules. In order to increase the attractiveness of this useful catalytic transformation, some Michael acceptors bearing challenging electron
Graphical Abstract
Scheme 1: Competitive side reactions in the Cu ECA of organometallic reagents to α,β-unsaturated aldehydes.
Scheme 2: Cu-catalyzed ECA of α,β-unsaturated aldehydes with phosphoramidite- (a) and phosphine-based ligands...
Scheme 3: One-pot Cu-catalyzed ECA/organocatalyzed α-substitution of enals.
Scheme 4: Combination of copper and amino catalysis for enantioselective β-functionalizations of enals.
Scheme 5: Optimized conditions for the Cu ECAs of R2Zn, RMgBr, and AlMe3 with α,β-unsaturated aldehydes.
Scheme 6: CuECA of Grignard reagents to α,β-unsaturated thioesters and their application in the asymmetric to...
Scheme 7: Improved Cu ECA of Grignard reagents to α,β-unsaturated thioesters, and their application in the as...
Scheme 8: Catalytic enantioselective synthesis of vicinal dialkyl arrays via Cu ECA of Grignard reagents to γ...
Scheme 9: 1,6-Cu ECA of MeMgBr to α,β,γ,δ-bisunsaturated thioesters: an iterative approach to deoxypropionate...
Scheme 10: Tandem Cu ECA/intramolecular enolate trapping involving 4-chloro-α,β-unsaturated thioester 22.
Scheme 11: Cu ECA of Grignard reagents to 3-boronyl α,β-unsaturated thioesters.
Scheme 12: Cu ECA of alkylzirconium reagents to α,β-unsaturated thioesters.
Scheme 13: Conversion of acylimidazoles into aldehydes, ketones, acids, esters, amides, and amines.
Scheme 14: Cu ECA of dimethyl malonate to α,β-unsaturated acylimidazole 31 with triazacyclophane-based ligand ...
Scheme 15: Cu/L13-catalyzed ECA of alkylboranes to α,β-unsaturated acylimidazoles.
Scheme 16: Cu/hydroxyalkyl-NHC-catalyzed ECA of dimethylzinc to α,β-unsaturated acylimidazoles.
Scheme 17: Stereocontrolled synthesis of 3,5,7-all-syn and anti,anti-stereotriads via iterative Cu ECAs.
Scheme 18: Stereocontrolled synthesis of anti,syn- and anti,anti-3,5,7-(Me,OR,Me) units via iterative Cu ECA/B...
Scheme 19: Cu-catalyzed ECA of dialkylzinc reagents to α,β-unsaturated N-acyloxazolidinones.
Scheme 20: Cu/phosphoramidite L16-catalyzed ECA of dialkylzincs to α,β-unsaturated N-acyl-2-pyrrolidinones.
Scheme 21: Cu/(R,S)-Josiphos (L9)-catalyzed ECA of Grignard reagents to α,β-unsaturated amides.
Scheme 22: Cu/Josiphos (L9)-catalyzed ECA of Grignard reagents to polyunsaturated amides.
Scheme 23: Cu-catalyzed ECA of trimethylaluminium to N-acylpyrrole derivatives.
Asymmetric synthesis of propargylamines as amino acid surrogates in peptidomimetics
- Matthias Wünsch,
- David Schröder,
- Tanja Fröhr,
- Lisa Teichmann,
- Sebastian Hedwig,
- Nils Janson,
- Clara Belu,
- Jasmin Simon,
- Shari Heidemeyer,
- Philipp Holtkamp,
- Jens Rudlof,
- Lennard Klemme,
- Alessa Hinzmann,
- Beate Neumann,
- Hans-Georg Stammler and
- Norbert Sewald
Beilstein J. Org. Chem. 2017, 13, 2428–2441, doi:10.3762/bjoc.13.240
- propargylamines by nucleophilic addition. The synthesis of propargylamines by diastereoselective reductive amination requires alkynyl ketones, which are difficult to prepare and are unstable towards reductive conditions. In approach I, organometallic nucleophiles are added to N-sulfinyl propargylimines, derived
- -butyl sulfinamide led to the enantiomerically pure sulfinylimines 3a and 3b, which were reacted with a variety of organometallic compounds, including iPrMgBr, MeMgBr and BnMgBr. The reaction of the enantiomerically pure N-sulfinylimines 3a and 3b with aliphatic organometallic nucleophiles resulted in
Graphical Abstract
Figure 1: Concept of carboxylic acid or amide bond replacement on the basis of an alkyne moiety.
Figure 2: Selection of reactions based on propargylamines as precursors. a) Intramolecular Pauson–Khand react...
Figure 3: Two different approaches for the stereoselective de novo synthesis of propargylamines using Ellman’...
Figure 4: Synthesis of propargylamines 4a and 4b by introducing the side chain as nucleophile. (a) HC≡CCH2OH,...
Figure 5: Reaction of N-sulfinylimine 5h with (trimethylsilyl)ethynyllithium. (a) GP-3 or GP-4. (b) Aqueous w...
Figure 6: Side reactions observed in the course of the conversion of highly electrophilic sulfinylimines 5. (...
Figure 7: a) Possible transition states TI and TII for the transfer of the methyl moiety from AlMe3 to the im...
Figure 8: Base-induced rearrangement of propargylamines bearing electron-withdrawing substituents.
Figure 9: Base-catalyzed rearrangement of propargylamines 11 to α,β-unsaturated imines 12. A) Reaction scheme...
Conjugate addition–enantioselective protonation reactions
- James P. Phelan and
- Jonathan A. Ellman
Beilstein J. Org. Chem. 2016, 12, 1203–1228, doi:10.3762/bjoc.12.116
- assembly of more complex structures from simple precursors. In this review the addition of diverse protic and organometallic nucleophiles to electron-deficient alkenes followed by enantioselective protonation is summarized. Reactions are first categorized by the type of electron-deficient alkene and then
Graphical Abstract
Figure 1: Two general pathways for conjugate addition followed by enantioselective protonation.
Scheme 1: Tomioka’s enantioselective addition of arylthiols to α-substituted acrylates.
Scheme 2: Sibi’s enantioselective hydrogen atom transfer reactions.
Scheme 3: Mikami’s addition of perfluorobutyl radical to α-aminoacrylate 11.
Scheme 4: Reisman’s Friedel–Crafts conjugate addition–enantioselective protonation approach toward tryptophan...
Scheme 5: Pracejus’s enantioselective addition of benzylmercaptan to α-aminoacrylate 20.
Scheme 6: Kumar and Dike’s enantioselective addition of thiophenol to α-arylacrylates.
Scheme 7: Tan’s enantioselective addition of aromatic thiols to 2-phthalimidoacrylates.
Scheme 8: Glorius’ enantioselective Stetter reactions with α-substituted acrylates.
Scheme 9: Dixon’s enantioselective addition of thiols to α-substituted acrylates.
Figure 2: Chiral phosphorous ligands.
Scheme 10: Enantioselective addition of arylboronic acids to methyl α-acetamidoacrylate.
Scheme 11: Frost’s enantioselective additions to dimethyl itaconate.
Scheme 12: Darses and Genet’s addition of potassium organotrifluoroborates to α-aminoacrylates.
Scheme 13: Proposed mechanism for enantioselective additions to α-aminoacrylates.
Scheme 14: Sibi’s addition of arylboronic acids to α-methylaminoacrylates.
Scheme 15: Frost’s enantioselective synthesis of α,α-dibenzylacetates 64.
Scheme 16: Rovis’s hydroheteroarylation of α-substituted acrylates with benzoxazoles.
Scheme 17: Proposed mechanism for the hydroheteroarylation of α-substituted acrylates with benzoxazoles.
Scheme 18: Sodeoka’s enantioselective addition of amines to N-benzyloxycarbonyl acrylamides 75 and 77.
Scheme 19: Proposed catalytic cycle for Sodeoka’s enantioselective addition of amines.
Scheme 20: Sibi’s enantioselective Friedel–Crafts addition of pyrroles to imides 84.
Scheme 21: Kobayashi’s enantioselective addition of malonates to α-substituted N-acryloyloxazolidinones.
Scheme 22: Chen and Wu’s enantioselective addition of thiophenol to N-methacryloyl benzamide.
Scheme 23: Tan’s enantioselective addition of secondary phosphine oxides and thiols to N-arylitaconimides.
Scheme 24: Enantioselective addition of thiols to α-substituted N-acryloylamides.
Scheme 25: Kobayashi’s enantioselective addition of thiols to α,β-unsaturated ketones.
Scheme 26: Feng’s enantioselective addition of pyrazoles to α-substituted vinyl ketones.
Scheme 27: Luo and Cheng’s addition of indoles to vinyl ketones by enamine catalysis.
Scheme 28: Curtin–Hammett controlled enantioselective addition of indole.
Scheme 29: Luo and Cheng’s enantioselective additions to α-branched vinyl ketones.
Scheme 30: Lou’s reduction–conjugate addition–enantioselective protonation.
Scheme 31: Luo and Cheng’s primary amine-catalyzed addition of indoles to α-substituted acroleins.
Scheme 32: Luo and Cheng’s proposed mechanism and transition state.
Figure 3: Shibasaki’s chiral lanthanum and samarium tris(BINOL) catalysts.
Scheme 33: Shibasaki’s enantioselective addition of 4-tert-butyl(thiophenol) to α,β-unsaturated thioesters.
Scheme 34: Shibasaki’s application of chiral (S)-SmNa3tris(binaphthoxide) catalyst 144 to the total synthesis ...
Scheme 35: Shibasaki’s cyanation–enantioselective protonation of N-acylpyrroles.
Scheme 36: Tanaka’s hydroacylation of acrylamides with aliphatic aldehydes.
Scheme 37: Ellman’s enantioselective addition of α-substituted Meldrum’s acids to terminally unsubstituted nit...
Scheme 38: Ellman’s enantioselective addition of thioacids to α,β,β-trisubstituted nitroalkenes.
Scheme 39: Hayashi’s enantioselective hydroarylation of diphenylphosphinylallenes.
Scheme 40: Hayashi’s enantioselective hydroarylation of diphenylphosphinylallenes.
Figure 4: Togni’s chiral ferrocenyl tridentate nickel(II) and palladium(II) complexes.
Scheme 41: Togni’s enantioselective hydrophosphination of methacrylonitrile.
Scheme 42: Togni’s enantioselective hydroamination of methacrylonitrile.
Copper-catalyzed asymmetric conjugate addition of organometallic reagents to extended Michael acceptors
- Thibault E. Schmid,
- Sammy Drissi-Amraoui,
- Christophe Crévisy,
- Olivier Baslé and
- Marc Mauduit
Beilstein J. Org. Chem. 2015, 11, 2418–2434, doi:10.3762/bjoc.11.263
- control of the regio- and enantioselectivity of the addition. The aim of this review is to report recent breakthroughs achieved in this challenging field. Keywords: conjugate additions; electron-deficient alkenes; enantioselective catalysis; extended Michael acceptors; organometallic nucleophiles
Graphical Abstract
Figure 1: Possible reaction pathways in conjugate additions of nucleophiles on extended Michael acceptors.
Figure 2: Early reports of conjugate addition of copper-based reagents to extended Michael acceptors.
Figure 3: First applications of copper catalyzed 1,6-ACA in total synthesis.
Scheme 1: First example of enantioselective copper-catalyzed ACA on an extended Michael acceptor.
Scheme 2: Meldrum’s acid derivatives as substrates in enantioselective ACA.
Scheme 3: Reactivity of a cyclic dienone in Cu-catalyzed ACA of diethylzinc.
Scheme 4: Efficiency of DiPPAM ligand in 1,6-ACA of dialkylzinc to cyclic dienones.
Scheme 5: Sequential 1,6/1,4-ACA reactions involving linear aryldienones.
Scheme 6: Unsymmetrical hydroxyalkyl NHC ligands in 1,6-ACA of cyclic dienones.
Scheme 7: Performance of atropoisomeric diphosphines in 1,6-ACA of Et2Zn on cyclic dienones.
Scheme 8: Selective 1,6-ACA of Grignard reagents to acyclic dienoates, application in total synthesis.
Scheme 9: Reactivity of polyenic linear thioesters towards sequential 1,6-ACA/reconjugation/1,4-ACA and produ...
Scheme 10: 1,6-Conjugate addition of trialkylaluminium with regards to cyclic dienones.
Scheme 11: Copper-catalyzed conjugate addition of trimethylaluminium onto nitro dienoates.
Scheme 12: Copper-catalyzed selective 1,4-ACA in total synthesis of erogorgiaene.
Scheme 13: 1,4-selective addition of diethylzinc onto a cyclic enynone catalyzed by a chiral NHC-based system.
Scheme 14: Cu-NHC-catalyzed 1,6-ACA of dimethylzinc onto an α,β,γ,δ-unsaturated acyl-N-methylimidazole.
Scheme 15: 1,4-Selectivity in conjugate addition on extended systems with the concomitant use of a chelating c...
Scheme 16: Cu-NHC catalyzed 1,4-ACA as the key step in the total synthesis of ent-riccardiphenol B.
Scheme 17: Cu-NHC-catalyzed 1,4-selective ACA reactions with enynones.
Scheme 18: Linear dienones as substrates in 1,4-asymmetric conjugate addition reactions of Grignard reagents c...
Scheme 19: 1,4-ACA of trimethylaluminium to a cyclic enynone catalyzed by a copper-NHC system.
Scheme 20: Generation of a sterically encumbered chiral cyclohexanone from a polyunsaturated cyclic Michael ac...
Scheme 21: Selective conversion of β,γ-unsaturated α-ketoesters in copper-catalyzed asymmetric conjugate addit...
Scheme 22: Addition of trialkylaluminium compounds to nitroenynes catalyzed by L9/CuTC.
Scheme 23: Addition of trialkylaluminium compounds to nitrodienes catalyzed by L9/CuTC.
Scheme 24: Copper catalyzed 1,8- and 1,10-ACA reactions.
One-pot functionalisation of N-substituted tetrahydroisoquinolines by photooxidation and tunable organometallic trapping of iminium intermediates
- Joshua P. Barham,
- Matthew P. John and
- John A. Murphy
Beilstein J. Org. Chem. 2014, 10, 2981–2988, doi:10.3762/bjoc.10.316
- novel, one-pot methodology that functionalises N-substituted tetrahydroisoquinolines by visible light-assisted photooxidation, followed by trapping of the resultant iminium ions with organometallic nucleophiles. This affords 1,2-disubstituted tetrahydroisoquinolines in moderate to excellent yields
- tolerated a wide range of organometallic nucleophiles [32] and Yu developed methodology for THIQ alkynylation which does not require N-aryl motifs [33]. We sought a general procedure for organometallic trapping of iminium salts generated by oxidative functionalisation; a methodology amenable to a range of
Graphical Abstract
Figure 1: Examples of biologically active 1,2-disubstituted tetrahydroisoquinolines.
Scheme 1: Oxidative C–H functionalisation and examples of previously reported nucleophilic trappings.
Figure 2: Products from allylzinc reagent addition to 5a and 5b.
Figure 3: Proposed mechanism for formation of side-product 8a. Analogous reactivity in the formation of cycli...
Figure 4: Mechanism for dimerisation of the allylzinc halide and β-hydride addition to 5a [36].
Scheme 2: A concise synthesis of methopholine (3).
Electrocarboxylation: towards sustainable and efficient synthesis of valuable carboxylic acids
- Roman Matthessen,
- Jan Fransaer,
- Koen Binnemans and
- Dirk E. De Vos
Beilstein J. Org. Chem. 2014, 10, 2484–2500, doi:10.3762/bjoc.10.260
- carboxylic acids from CO2 under relatively mild conditions, reactive organometallic nucleophiles such as Grignard reagents can be used, generating a large amount of waste [21][22][23][24]. Electroreduction of CO2 can be a worthy alternative for these dangerous energy-intensive processes, replacing toxic or
Graphical Abstract
Scheme 1: Synthesis of salicylic acid and p-hydroxybenzoic acid via Kolbe–Schmidt reaction [16-20].
Scheme 2: Electroreduction of carbon dioxide to formic acid, methanol or methane.
Scheme 3: Electrochemical fixation of CO2 in olefins.
Scheme 4: Electrohydrodimerisation of acrylonitrile to adiponitrile [32].
Scheme 5: Parallel paired electrosynthesis of phthalide and tert-butylbenzaldehyde dimethylacetal [34].
Scheme 6: Overview of electrocarboxylation setups using (a) a sacrificial anode, (b) an inert anode, generati...
Scheme 7: General mechanism of the electrochemical dicarboxylation of conjugated dienes [49].
Scheme 8: Reported anodic reactions for the electrocarboxylation of 1,3-butadiene.
Scheme 9: General mechanism for electrocarboxylation of alkynes.
Scheme 10: Electrocarboxylation of ethyl cinnamate [70].
Scheme 11: General electrocarboxylation mechanism for carbonyl compounds (Y = O) and imines (Y = NH) [75-77].
Scheme 12: Electrocarboxylation mechanism of butyraldehyde proposed by Doherty [78].
Scheme 13: Electrocarboxylation of AMN to HN using a sacrificial aluminum anode [86].
Scheme 14: Electrocarboxylation of benzalaniline using a sacrificial aluminum anode [105].
Scheme 15: Electrocarboxylation of p-isobutylacetophenone with stable electrodes [94,95].
Scheme 16: Electrochemical carboxylation of MMP to MHA [110,111].
Scheme 17: General mechanism for electrocarboxylation of alkyl halides [122,124-126,128].
Scheme 18: Electrocarboxylation of benzylic chlorides as synthesis route for NSAIDs.
Scheme 19: Electrocarboxylation of 1,4-dibromo-2-butene [144].
Scheme 20: Convergent paired electrosynthesis of cyanoacetic acid, with X− = F4B−, ClO4−, HSO4−, Cl−, Br− [147].
Scheme 21: General scheme of carboxylation of weak acidic hydrocarbons with electrogenerated bases. RH: weakly...
Scheme 22: Electrocarboxylation of N-methyldiglycolimide to methoxymethane-1,1,1’-tricarboxylate precursors. R1...
Scheme 23: Electrochemical dimerization of CO2 with stable electrodes [153].
Preparation of phosphines through C–P bond formation
- Iris Wauters,
- Wouter Debrouwer and
- Christian V. Stevens
Beilstein J. Org. Chem. 2014, 10, 1064–1096, doi:10.3762/bjoc.10.106
- phosphine boranes 12a via substitution of the chlorine atom with organometallic nucleophiles. This substitution causes an inversion of configuration at the phosphorus center (Scheme 3). Schuman et al. have prepared several dialkenylphosphines using this methodology [40]. Nucleophilic substitution with
Graphical Abstract
Scheme 1: Synthesis of P-stereogenic phosphines 5 using menthylphosphinite borane diastereomers 2.
Scheme 2: Enantioselective synthesis of chiral phosphines 10 with ephedrine as a chiral auxiliary.
Scheme 3: Chlorophosphine boranes 11a as P-chirogenic electrophilic building blocks.
Scheme 4: Monoalkylation of phenylphosphine borane 15 with methyl iodide in the presence of Cinchona alkaloid...
Scheme 5: Preparation of tetraphosphine borane 19.
Scheme 6: Using chiral chlorophosphine-boranes 11b as phosphide borane 20 precursors.
Scheme 7: Nickel-catalyzed cross-coupling (dppe = 1,2-bis(diphenylphosphino)ethane).
Scheme 8: Pd-catalyzed cross-coupling reaction with organophosphorus stannanes 30.
Scheme 9: Copper iodide catalyzed carbon–phosphorus bond formation.
Scheme 10: Thermodynamic kinetic resolution as the origin of enantioselectivity in metal-catalyzed asymmetric ...
Scheme 11: Ru-catalyzed asymmetric phosphination of benzyl and alkyl chlorides 35 with HPPhMe (36a, PHOX = pho...
Scheme 12: Pt-catalyzed asymmetric alkylation of secondary phosphines 36b.
Scheme 13: Different adducts 43 can result from hydrophosphination.
Scheme 14: Pt-catalyzed asymmetric hydrophosphination.
Scheme 15: Intramolecular hydrophosphination of phosphinoalkene 47.
Scheme 16: Organocatalytic asymmetric hydrophosphination of α,β-unsaturated aldehydes 59.
Scheme 17: Preparation of phosphines using zinc organometallics.
Scheme 18: Preparation of alkenylphosphines 71a from alkenylzirconocenes 69 (dtc = N,N-diethyldithiocarbamate,...
Scheme 19: SNAr with P-chiral alkylmethylphosphine boranes 13c.
Scheme 20: Synthesis of QuinoxP 74 (TMEDA = tetramethylethylenediamine).
Scheme 21: Pd-Mediated couplings of a vinyl triflate 76 with diphenylphosphine borane 13e.
Figure 1: Menthone (83) and camphor (84) derived chiral phosphines.
Scheme 22: Palladium-catalyzed cross-coupling reaction of vinyl tosylates 85 and 87 with diphenylphosphine bor...
Scheme 23: Attempt for the enantioselective palladium-catalyzed C–P cross-coupling reaction between an alkenyl...
Scheme 24: Enol phosphates 88 as vinylic coupling partners in the palladium-catalyzed C–P cross-coupling react...
Scheme 25: Nickel-catalyzed cross-coupling in the presence of zinc (dppe = 1,2-bis(diphenylphosphino)ethane).
Scheme 26: Copper-catalyzed coupling of secondary phosphines with vinyl halide 94.
Scheme 27: Palladium-catalyzed cross-coupling of aryl iodides 97 with organoheteroatom stannanes 30.
Scheme 28: Synthesis of optically active phosphine boranes 100 by cross-coupling with a chiral phosphine boran...
Scheme 29: Palladium-catalyzed P–C cross-coupling reactions between primary or secondary phosphines and functi...
Scheme 30: Enantioselective synthesis of a P-chirogenic phosphine 108.
Scheme 31: Enantioselective arylation of silylphosphine 110 ((R,R)-Et-FerroTANE = 1,1'-bis((2R,4R)-2,4-diethyl...
Scheme 32: Nickel-catalyzed arylation of diphenylphosphine 25d.
Scheme 33: Nickel-catalyzed synthesis of (R)-BINAP 116 (dppe = 1,2-bis(diphenylphosphino)ethane, DABCO = 1,4-d...
Scheme 34: Nickel-catalyzed cross-coupling between aryl bromides 119 and diphenylphosphine (25d) (dppp = 1,3-b...
Scheme 35: Stereocontrolled Pd(0)−Cu(I) cocatalyzed aromatic phosphorylation.
Scheme 36: Preparation of alkenylphosphines by hydrophosphination of alkynes.
Scheme 37: Palladium and nickel-catalyzed addition of P–H to alkynes 125a.
Scheme 38: Palladium-catalyzed asymmetric hydrophosphination of an alkyne 128.
Scheme 39: Ruthenium catalyzed hydrophosphination of propargyl alcohols 132 (cod = 1,5-cyclooctadiene).
Scheme 40: Cobalt-catalyzed hydrophosphination of alkynes 134a (acac = acetylacetone).
Scheme 41: Tandem phosphorus–carbon bond formation–oxyfunctionalization of substituted phenylacetylenes 125c (...
Scheme 42: Organolanthanide-catalyzed intramolecular hydrophosphination/cyclization of phosphinoalkynes 143.
Scheme 43: Hydrophosphination of alkynes 134c catalyzed by ytterbium-imine complexes 145 (hmpa = hexamethylpho...
Scheme 44: Calcium-mediated hydrophosphanylation of alkyne 134d.
Scheme 45: Formation and substitution of bromophosphine borane 151.
Scheme 46: General scheme for a nickel or copper catalyzed cross-coupling reaction.
Scheme 47: Copper-catalyzed synthesis of alkynylphosphines 156.
Radical zinc-atom-transfer-based carbozincation of haloalkynes with dialkylzincs
- Fabrice Chemla,
- Florian Dulong,
- Franck Ferreira and
- Alejandro Pérez-Luna
Beilstein J. Org. Chem. 2013, 9, 236–245, doi:10.3762/bjoc.9.28
- organometallic nucleophiles and undergo intramolecular nucleophilic substitution reactions [47][48][49][50][51]. Experimental Experiments involving organometallic compounds were carried out in dried glassware under a positive pressure of dry Ar. All solvents were distilled to remove stabilizers and dried with a
Graphical Abstract
Scheme 1: Anticipated formation of alkylidene zinc carbenoids by reaction of dialkylzincs with β-(propargylox...
Scheme 2: Preparation of β-(propargyloxy)enoates having pendant haloalkynes. Reagents and conditions: (a) 2 (...
Scheme 3: Possible reaction pathways to account for the formation of product 5.
Scheme 4: Test experiments to gain insight into the mechanism of formation of alkylidene zinc intermediate 7.
Scheme 5: Mechanistic rationale for the reaction of dialkylzincs with β-(propargyloxy)enoate 3a.
A practical route to tertiary diarylmethylamides or -carbamates from imines, organozinc reagents and acyl chlorides or chloroformates
- Erwan Le Gall,
- Antoine Pignon and
- Thierry Martens
Beilstein J. Org. Chem. 2011, 7, 997–1002, doi:10.3762/bjoc.7.112
- previous studies reporting the activation of imines under an acyliminium form and the subsequent addition of either aromatic [17][18][19][20][21][22][23][26][27] or non-aromatic [34][35] organometallic nucleophiles onto carbon. Our preliminary investigations were then conducted on N-benzylidenepropan-1
Graphical Abstract
Scheme 1: Addition of nucleophiles onto activated imines (A) or iminiums (B).
Scheme 2: Activation of the aldimine with MsCl.
An exceptional P-H phosphonite: Biphenyl- 2,2'-bisfenchylchlorophosphite and derived ligands (BIFOPs) in enantioselective copper- catalyzed 1,4-additions
- T. Kop-Weiershausen,
- J. Lex,
- J.-M. Neudörfl and
- B. Goldfuss
Beilstein J. Org. Chem. 2005, 1, No. 6, doi:10.1186/1860-5397-1-6
- as well as hydridic and organometallic nucleophiles. Chloride substitution in BIFOP-Cl proceeds only under drastic conditions. New enantiopure, sterically demanding phosphorus ligands such as a phosphoramidite, a phosphite and a P-H phosphonite (BIFOP-H) are hereby accessible. In enantioselective Cu
Graphical Abstract
Scheme 1: Monodentate phosphorus ligands, e.g. BINOL-based phosphoramidites or TADDOL-based phosphites, are h...
Scheme 2: Modular phosphoramidites (R= NR'2) or phosphites (R= OR') from reactive chlorophosphite intermediat...
Figure 1: X-ray crystal structure of BIFOP-Cl (1). Distances are given in Å. (BAA = biaryl angle between C2-C1...
Figure 2: X-ray structures of BIFOP-Br (2). Distances are given in Å. (BAA = biaryl angle between C2-C1-C1'-C2...
Scheme 3: Synthesis of biphenyl-2,2'-bisfenchol (BIFOL) based phosphane derivatives (BIFOPs).
Figure 3: X-ray structures of BIFOP-H (3). Distances are given in Å. (BAA = biaryl angle between C2-C1-C1'-C2...
Figure 4: X-ray structures of BIFOP-nBu (5). Distances are given in Å. (BAA = biaryl angle between C2-C1-C1'-C...
Figure 5: X-ray structures of BIFOP(O)-H (8). Distances are given in Å. (BAA = biaryl angle between C2-C1-C1'...
Figure 6: X-ray structures of phosphite BIFOP-OPh (6). Distances are given in Å. (BAA = biaryl angle between C...
Figure 7: X-ray structures of phosphoramidite BIFOP-NEt2 (7). Distances are given in Å. (BAA = biaryl angle b...
Figure 8: X-ray structures of BIFOP(O)-Cl (9). Distances are given in Å. (BAA = biaryl angle between C2-C1-C1...
Scheme 4: Geometries of BIFOP-systems with respect to biaryl dihedral angles (C2-C1-C1’-C2’, BAA), fenchyl-ar...
Figure 9: Computed geometry (PM3) of plus-(P)-BIFOP-Cl with unnatural plus-(P)-biaryl conformation. Distances...
Scheme 5: Biphenyl-2,2'-bisfenchol based phosphanes (BIFOPs) as chiral ligands in enantioselective Cu-catalyz...
Scheme 6: Anharmonic B3LYP/6-31G*(C,H,N,O,F,Cl,Br) /SDD(Cu) CO-stretching frequencies to assess metal to liga...
