Enantioselective synthesis of β-aryl-γ-lactam derivatives via Heck–Matsuda desymmetrization of N-protected 2,5-dihydro-1H-pyrroles

• Arnaldo G. de Oliveira Jr.,
• Martí F. Wang,
• Rafaela C. Carmona,
• Danilo M. Lustosa,
• Sergei A. Gorbatov and
• Carlos R. D. Correia

Beilstein J. Org. Chem. 2024, 20, 940–949, doi:10.3762/bjoc.20.84

• , key five-membered olefins bearing heteroatoms can provide direct access to chiral sulfones, sulfoxides, phosphine oxides [8], phthalides, isochromanones, and lactones [9] in a very efficient and convenient manner. Despite our previous results in this area, the desymmetrization of 2,5-dihydro-1H

Selective and scalable oxygenation of heteroatoms using the elements of nature: air, water, and light

• Damiano Diprima,
• Hannes Gemoets,
• Stefano Bonciolini and
• Koen Van Aken

Beilstein J. Org. Chem. 2023, 19, 1146–1154, doi:10.3762/bjoc.19.82

• retardants [14]. Sulfoxides are prominent pharmaceutical ingredients, while phosphine oxides improve solubility of corresponding compounds [15] and have applications in catalysis and materials science [16]. Selenoxides find use as oxygen transfer agents and donor ligands in metal catalysis and organic

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• of α,β-unsaturated phosphine oxides 149 [79]. Their work also included an example of the consecutive trapping of the enolate by MeI (Scheme 38). Using the (R,Sp)-Josiphos ligand (L17), the product of the tandem reaction (150) was gained in 63% yield (dr 5.2:1). At the beginning of the new decade

Improving the accuracy of ³¹P NMR chemical shift calculations by use of scaling methods

• William H. Hersh and
• Tsz-Yeung Chan

Beilstein J. Org. Chem. 2023, 19, 36–56, doi:10.3762/bjoc.19.4

• the corresponding phosphine oxides 33[O] and 34[O] with chemical shifts of 38 and 26 ppm, respectively (Figure 7). Identification of the isomers by 31P NMR would represent a nice example of the utility of the calculations described here. Results for 33, 34, 33[O], and 34[O] all confirmed the 1966

Lewis acid-catalyzed Pudovik reaction–phospha-Brook rearrangement sequence to access phosphoric esters

• Jin Yang,
• Dang-Wei Qian and
• Shang-Dong Yang

Beilstein J. Org. Chem. 2022, 18, 1188–1194, doi:10.3762/bjoc.18.123

• examined a series of reactions of symmetric and asymmetric secondary phosphine oxides with 2-pyridinecarboxaldehyde (2a), which produced the corresponding O-phosphination products (Scheme 2). Diarylphosphine oxide substrates with either electron-withdrawing or electron-donating groups tethered to the

• system was further demonstrated with various unsymmetrically substituted phosphine oxides under the standard conditions. When the aryl group in the diarylphosphine oxide substrate was replaced by one or two alkyl groups or an ethoxy group, the transformation could also be achieved in moderate to good

• esters and provides a scope complementary to previous similar base-catalyzed transformation. Different strategies for phospha-Brook reactions. Scope of 1 (secondary phosphine oxides and phosphonate). Reaction conditions: 1 (0.2 mmol), 2-pyridinecarboxaldehyde (2a, 0.3 mmol), Cu(OTf)2 (10 mol %), THF (2

Synthesis, structural characterization, and optical properties of benzo[f]naphtho[2,3-b]phosphoindoles

• Mio Matsumura,
• Takahiro Teramoto,
• Masato Kawakubo,
• Masatoshi Kawahata,
• Yuki Murata,
• Kentaro Yamaguchi,
• Masanobu Uchiyama and
• Shuji Yasuike

Beilstein J. Org. Chem. 2021, 17, 671–677, doi:10.3762/bjoc.17.56

• approaches for phosphine oxide B [12][13][14], alkylated products C [15], and transition metal complexes D [16][17] have also been developed. However, for isomers E [18][19] and G [20], only the synthetic method for pentavalent phosphine oxides has been reported. To the best of our knowledge, the synthesis

CF₃-substituted carbocations: underexploited intermediates with great potential in modern synthetic chemistry

• Anthony J. Fernandes,
• Armen Panossian,
• Bastien Michelet,
• Agnès Martin-Mingot,
• Frédéric R. Leroux and
• Sébastien Thibaudeau

Beilstein J. Org. Chem. 2021, 17, 343–378, doi:10.3762/bjoc.17.32

• progressive conversion of the starting material into the C6-derivative 64 (Scheme 18). Chen et al. reported the synthesis of C2-phosphorylated indoles via 1,2-phosphorylation of 3-indolylmethanols with H-phosphine oxides or H-phosphonates under Brønsted acid activation [72]. The scope of the reaction includes

Metal-free synthesis of phosphinoylchroman-4-ones via a radical phosphinoylation–cyclization cascade mediated by K₂S₂O₈

• Qiang Liu,
• Weibang Lu,
• Guanqun Xie and
• Xiaoxia Wang

Beilstein J. Org. Chem. 2020, 16, 1974–1982, doi:10.3762/bjoc.16.164

• , we successfully separated a small amount of byproduct 4 which was identified by NMR spectroscopy. These experiments clearly support a phosphorus-centered radical reaction pathway. It has been reported that phosphorus-centered radicals could be generated from phosphine oxides in the presence of

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

• , mild oxidizing additives such as amine oxides, aminophosphines, phosphine oxides, and sulfoxides may be used as promoters to facilitate the dissociation step, by oxidatively removing one of the CO ligands in form of CO2 [40]. The most common oxidants are N-morpholine N-oxide (NMO), trimethylamine N

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

• usually lead to stereoselective reduction products, hence, they are used for the synthesis of chiral phosphines from chiral oxides [53]. Lithium tetrahydridoaluminate is used for the reduction of achiral phosphines because its action on optically active phosphine oxides leads mainly to the optically

[1,3]/[1,4]-Sulfur atom migration in β-hydroxyalkylphosphine sulfides

• Katarzyna Włodarczyk,
• Piotr Borowski and
• Marek Stankevič

Beilstein J. Org. Chem. 2020, 16, 88–105, doi:10.3762/bjoc.16.11

• for β-hydroxyalkylphosphine oxides [56][57], this led to the formation of cyclic phosphine oxides 3 and 26 rather than phosphine sulfides. It may be assumed that hydrolysis of the P=S bond occurred under these reaction conditions and, probably, racemization of the phosphorus center in the case of

• was in accordance with the shifts of this group in other phosphine oxides [61][62][63]. Moreover, the two signals at 2.91–2.98 and 3.16–3.24 ppm, respectively, corresponded to a hydrogen atom bonded to a sulfur atom [64][65]. Even more conclusive was the analysis of the 13C NMR spectra of 12 and 29

• stereoselectivity. It was found that the P-stereogenic β-/γ-mercaptoalkylphosphine oxides underwent intramolecular cyclization to the corresponding bicyclic phosphine oxides with high stereoselectivity and high yield under mild reaction conditions. 1H NMR spectra of compounds 12 and 29. 13C NMR spectra of compounds

Chiral terpene auxiliaries V: Synthesis of new chiral γ-hydroxyphosphine oxides derived from α-pinene

• Anna Kmieciak and
• Marek P. Krzemiński

Beilstein J. Org. Chem. 2019, 15, 2493–2499, doi:10.3762/bjoc.15.242

• with chlorophosphines, the reaction of metal phosphides with haloalkanes, and transition-metal-catalyzed cross-coupling reactions to form C–P bonds are the most widely used methods for the synthesis of phosphines [13][14]. Since phosphines are easily oxidized to phosphine oxides, the addition of

• . Unfortunately, due to the probably too rigid bicyclic structure of the diphenylphosphinites, they did not undergo the sigmatropic rearrangement to the corresponding phosphine oxides. Further research and application of the obtained ligands are in progress. Experimental Diphenyl(((1R,2R,5S)-δ-pinen-3-yl)methyl

Microwave-assisted synthesis of N,N-bis(phosphinoylmethyl)amines and N,N,N-tris(phosphinoylmethyl)amines bearing different substituents on the phosphorus atoms

• Erika Bálint,
• Anna Tripolszky,
• László Hegedűs and
• György Keglevich

Beilstein J. Org. Chem. 2019, 15, 469–473, doi:10.3762/bjoc.15.40

• phosphorus atoms was synthesized by the microwave-assisted and catalyst-free Kabachnik–Fields reaction of (aminomethyl)phosphine oxides with paraformaldehyde and diphenylphosphine oxide. The three-component condensation of N,N-bis(phosphinoylmethyl)amine, paraformaldehyde and a secondary phosphine oxide

• affording N,N,N-tris(phosphinoylmethyl)amine derivatives was also elaborated. This method is a novel approach for the synthesis of the target products. Keywords: (aminomethyl)phosphine oxides; Kabachnik–Fields reaction; ligand; microwave; N,N-bis(phosphinoylmethyl)amines; N,N,N-tris(phosphinoylmethyl

• elaborated by us for the synthesis of several (aminomethyl)phosphine oxides [10][11]. As regards α-aminophosphine oxides with different P-substituents, only two different types were reported. Olszewski and co-workers synthesized chiral thiazole-substituted aminophosphine oxides 2 through the Pudovik reaction

Sigmatropic rearrangements of cyclopropenylcarbinol derivatives. Access to diversely substituted alkylidenecyclopropanes

• Guillaume Ernouf,
• Jean-Louis Brayer,
• Christophe Meyer and
• Janine Cossy

Beilstein J. Org. Chem. 2019, 15, 333–350, doi:10.3762/bjoc.15.29

• [2,3]-sigmatropic rearrangement of the in situ-generated phosphinites 2a–h. Primary or tertiary cyclopropenylcarbinols reacted equally well, as shown with the formation of phosphine oxides 3a (94%), 3b (93%) and 3c (87%). The [2,3]-sigmatropic rearrangement of phosphinites 2d–h derived from secondary

• cyclopropenylcarbinols led to the corresponding phosphine oxides 3d–h (85–93%) as a 80:20 mixture of E/Z geometric isomers, regardless of the substituent of the alcohol (at C4) and of the cyclopropene (at C2, Scheme 2) [33][34]. The [2,3]-sigmatropic rearrangement of an optically enriched phosphinite 2f, prepared from

• corresponding diastereomeric phosphine oxides 7a/7’a, even upon prolonged heating (toluene, 110 °C), and underwent slow decomposition instead (Scheme 5). This observation was in agreement with DFT calculations which indicated that the rearrangement of cyclopropenylmethyl phosphinite I, although

Non-metal-templated approaches to bis(borane) derivatives of macrocyclic dibridgehead diphosphines via alkene metathesis

• Tobias Fiedler,
• Michał Barbasiewicz,
• Michael Stollenz and
• John A. Gladysz

Beilstein J. Org. Chem. 2018, 14, 2354–2365, doi:10.3762/bjoc.14.211

• . Oxidations that lead to the corresponding dibridgehead diphosphine dioxides (O=)P((CH2)n)3P(=O) have exhibited promise, but purification has been problematic [24]. Indeed, phosphine oxides are everyday precursors to phosphines, so we have considered various non-metal-templated routes to 2·2(=O), 3·2(=O), and

• easily deprotected to give the respective isomers of the dibridgehead diphosphine 2 in high yields. Since phosphine oxides are also easily converted to phosphines, one could consider parallel approaches to 2 via metatheses of the phosphine oxide (O=)P((CH2)6CH=CH2)3 (1(=O)) or diphosphine dioxide (H2C=CH

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• this protocol. Different organophosphorus compounds including phosphine oxides, phosphinate ester, and phosphonate diester underwent C–P bond formation to give 22–94% of yield (Scheme 42). This method was also found to be applicable in gram scale synthesis with excellent yield. Mechanistically they

Synthesis of benzothiophene and indole derivatives through metal-free propargyl–allene rearrangement and allyl migration

• Jinzhong Yao,
• Yajie Xie,
• Lianpeng Zhang,
• Yujin Li and
• Hongwei Zhou

Beilstein J. Org. Chem. 2017, 13, 1866–1870, doi:10.3762/bjoc.13.181

• . Synthesis of 1-methylindole phosphine oxides. Reaction conditions: 3 (0.5 mmol), (EtO)2PCl (0.6 mmol), Et3N (1.5 mmol), and THF (2.0 mL) at −78 °C. Yields are isolated yield. Proposal of applicable β-sulfonium carbanion. Proposal of indole synthesis via allenylphosphonates. Optimization of the reaction

The synthesis of α-aryl-α-aminophosphonates and α-aryl-α-aminophosphine oxides by the microwave-assisted Pudovik reaction

• Erika Bálint,
• Ádám Tajti,
• Anna Ádám,
• István Csontos,
• Konstantin Karaghiosoff,
• Mátyás Czugler,
• Péter Ábrányi-Balogh and
• György Keglevich

Beilstein J. Org. Chem. 2017, 13, 76–86, doi:10.3762/bjoc.13.10

• the dialkyl phosphite were applied [43][44][45][46][47][48][49][50][51][52]. The synthesis of α-aryl-α-aminophosphine oxides by the addition of secondary phosphine oxides to imines is much less studied. Only a few publications were found and the reported reactions were performed in solvent (in DEE

Catalytic Wittig and aza-Wittig reactions

• Zhiqi Lao and
• Patrick H. Toy

Beilstein J. Org. Chem. 2016, 12, 2577–2587, doi:10.3762/bjoc.12.253

• covers the field of related catalytic aza-Wittig reactions that are catalyzed by both phosphine oxides and phosphines. Keywords: aza-Wittig reactions; catalysis; phosphines; phosphine oxides; reduction; silanes; Wittig reactions; Introduction The Wittig reaction is a venerable transformation for

• Wittig reaction distils down to identifying and implementing selective reducing conditions that enables the necessary catalyst redox cycling, yet does not reduce either the starting materials or the desired alkene-containing product. Arsine and telluride-catalyzed reactions As phosphine oxides are

• generally very stable and relatively difficult to reduce, the group of Yao-Zeng Huang used their prior findings that arsonium ylides can participate in Wittig-type reactions. Further they found that arsine oxides can be reduced using much milder reaction conditions compared to phosphine oxides. They

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

• enatiofacial selectivity, the use of a cyclic imide ensured exclusive formation of the Z-enolate. During optimization, it was found that an N-aryl group containing 2,6-disubstitution was crucial for obtaining high levels of enantioselectivity. Addition of a variety of bis-aryl secondary phosphine oxides

• nitroalkene [67]. α,β-Unsaturated phosphonates and phosphine oxides Transition metal catalysts In 2006, Hayashi and co-workers reported the first conjugate addition–enantioselective protonation of allenes 165 bearing a phosphine oxide (Scheme 39) [68]. Incorporation of the phosphine oxide allowed for

• enantioselective Friedel–Crafts addition of pyrroles to imides 84. Kobayashi’s enantioselective addition of malonates to α-substituted N-acryloyloxazolidinones. Chen and Wu’s enantioselective addition of thiophenol to N-methacryloyl benzamide. Tan’s enantioselective addition of secondary phosphine oxides and

Aerobic addition of secondary phosphine oxides to vinyl sulfides: a shortcut to 1-hydroxy-2-(organosulfanyl)ethyl(diorganyl)phosphine oxides

• Svetlana F. Malysheva,
• Alexander V. Artem’ev,
• Nina K. Gusarova,
• Nataliya A. Belogorlova,
• Alexander I. Albanov,
• C. W. Liu and
• Boris A. Trofimov

Beilstein J. Org. Chem. 2015, 11, 1985–1990, doi:10.3762/bjoc.11.214

• Chemistry, National Dong Hwa University, Hualien 97401, Taiwan 10.3762/bjoc.11.214 Abstract Secondary phosphine oxides react with vinyl sulfides (both alkyl- and aryl-substituted sulfides) under aerobic and solvent-free conditions (80 °C, air, 7–30 h) to afford 1-hydroxy-2-(organosulfanyl)ethyl(diorganyl

• )phosphine oxides in 70–93% yields. Keywords: addition; green method; phosphine oxides; regioselectivity; vinyl sulfides; Findings Tertiary phosphines and phosphine chalcogenides are important organophosphorus compounds that are widely used in industry, organic synthesis, polymer science, medicinal and

• %). The substrate scope includes both EDG- and EWG-substituted alkenes [27][28][29]. In this letter, we report our serendipitous finding that secondary phosphine oxides 1a–f under aerobic conditions (air, 80 °C, 7–18 h) easily add to vinyl sulfides 2a–c to give unknown 1-hydroxy-2-(organosulfanyl)ethyl

Synthesis of γ-hydroxypropyl P-chirogenic (±)-phosphorus oxide derivatives by regioselective ring-opening of oxaphospholane 2-oxide precursors

• Iris Binyamin,
• Shoval Meidan-Shani and
• Nissan Ashkenazi

Beilstein J. Org. Chem. 2015, 11, 1332–1339, doi:10.3762/bjoc.11.143

• Iris Binyamin Shoval Meidan-Shani Nissan Ashkenazi Department of Organic Chemistry, IIBR-Israel Institute for Biological Research, P.O. Box 19, Ness Ziona, 74100, Israel 10.3762/bjoc.11.143 Abstract The synthesis of P-chirogenic (±)-phosphine oxides and phosphinates via selective nucleophilic

• ; oxaphospholanes; phosphinates; phosphine oxides; Introduction Organophosphorus compounds containing phosphorus to carbon bond(s) are widely used in organic transformations. Textbook examples are the Wittig and the Horner–Wadsworth–Emmons reactions. Moreover, the vast majority of ligands used in organometallic

• various Grignard reagents. Indeed, in all cases, the attack on the phosphorus atom led exclusively to ring opening via endocyclic P–O bond cleavage and formation of a new P–C bond, yielding phosphinates and phosphine oxides with three different substituents on the phosphorus atom. Results and Discussion

Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams

• Katherine M. Byrd

Beilstein J. Org. Chem. 2015, 11, 530–562, doi:10.3762/bjoc.11.60

• enantioselectivity. In 2010, Wang and co-workers expanded their methodology to the 1,4-addition of phosphine oxides. Similar to their previous work, this reaction provided the products in high yields and enantioselecitives [266] (Scheme 40). 2.5 ECA employing organocatalysts Organocatalysts have become powerful

Synthesis of dinucleoside acylphosphonites by phosphonodiamidite chemistry and investigation of phosphorus epimerization

• William H. Hersh

Beilstein J. Org. Chem. 2015, 11, 184–191, doi:10.3762/bjoc.11.19

• acylphosphonite would require different nucleoside moieties. One example can be found in the literature of a non-Arbuzov route leading to the dinucleoside analog of 3 where as reported by Hata et al., 3a [41] gives 3b via sequential coupling [42][43] (Scheme 1). While the deoxygenation of phosphine oxides is

P(O)R₂-directed Pd-catalyzed C–H functionalization of biaryl derivatives to synthesize chiral phosphorous ligands

• Rong-Bin Hu,
• Hong-Li Wang,
• Hong-Yu Zhang,
• Heng Zhang,
• Yan-Na Ma and
• Shang-dong Yang

Beilstein J. Org. Chem. 2014, 10, 2071–2076, doi:10.3762/bjoc.10.215

• group not only achieved the directing role but also acts as an important component unit of the C–H functionalized products. In this paper, we use the axially chiral biaryl phosphine oxides as substrates and report the synthesis of various chiral phosphorus ligands with high enantiomeric selectivity