Search results

Search for "hydroboration" in Full Text gives 57 result(s) in Beilstein Journal of Organic Chemistry.

Recent advances in Cu-catalyzed C(sp3)–Si and C(sp3)–B bond formation

  • Balaram S. Takale,
  • Ruchita R. Thakore,
  • Elham Etemadi-Davan and
  • Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

Graphical Abstract
  • . This step is then followed by treatment of the reaction intermediate with an electrophile to deliver the desired borylated compound [98]. An efficient Cu-catalyzed (via in situ formed [(R)-DTBM-Segphos]CuH) protocol for an asymmetric net hydroboration of internal alkenes 343 with high regio- and
PDF
Album
Review
Published 15 Apr 2020

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

Graphical Abstract
  • ]-sigmatropic rearrangement of allyldiphenylphosphinites, obtained from (1R,2R,4S,5R)-3-methyleneneoisoverbanol and (1R,2R,3R,5R)-4-methyleneneoisopinocampheol, to allylphosphine oxides. Hydroxy groups were introduced stereoselectively through a hydroboration–oxidation reaction proceeding from the less hindered
  • (III) chloride in methanol in 88% yield (Scheme 1). The synthesis of allylic alcohol 11, a regioisomer of 6, started again from (1R)-α-pinene (1, Scheme 2). Hydroboration of (1R)-α-pinene with borane–dimethyl sulfide adduct (BMS) and crystallization of the product diisopinocampheylborane (dIpc2BH, 84
  • % yield. The allylic diphenylphosphine oxide 21 was subjected to the hydroboration–oxidation reaction introducing stereoselectively the hydroxy group. Hydroboration was carried out with an excess of borane–dimethyl sulfide adduct followed by the oxidation step. The standard C–B bond oxidation protocol
PDF
Album
Supp Info
Full Research Paper
Published 22 Oct 2019

Current understanding and biotechnological application of the bacterial diterpene synthase CotB2

  • Ronja Driller,
  • Daniel Garbe,
  • Norbert Mehlmer,
  • Monika Fuchs,
  • Keren Raz,
  • Dan Thomas Major,
  • Thomas Brück and
  • Bernhard Loll

Beilstein J. Org. Chem. 2019, 15, 2355–2368, doi:10.3762/bjoc.15.228

Graphical Abstract
  • include epoxidation resulting in 3,4-epoxy-7,18-dolabelladien-14-one (13) or hydroboration of 3,7,18-dolabellatriene (12, Scheme 1) that has been previously biotechnologically manufactured using CotB2W288G [103]. Another successful example is the oxidative transformation of cattleyene and phomopsen [104
PDF
Album
Review
Published 02 Oct 2019

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

  • Gagandeep Kour Reen,
  • Ashok Kumar and
  • Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

Graphical Abstract
  • , recyclable catalyst in the N-arylation of indoles [45][46]. Copper catalysts have shown exceptional enantioselectivity for reactions such as hydrosilylation, hydroboration, and heterogeneous as well as homogeneous hydrogenation [47][48][49]. Also, the copper salts found used as oxidants in a number of
PDF
Album
Review
Published 19 Jul 2019

Anomeric sugar boronic acid analogues as potential agents for boron neutron capture therapy

  • Daniela Imperio,
  • Erika Del Grosso,
  • Silvia Fallarini,
  • Grazia Lombardi and
  • Luigi Panza

Beilstein J. Org. Chem. 2019, 15, 1355–1359, doi:10.3762/bjoc.15.135

Graphical Abstract
  • position. The analogues were obtained by hydroboration of proper open-chain terminal alkenes that, after quenching with water, spontaneously afforded cyclic boronic acids with hemiacetal-like structures. Keywords: antitumor agents; boron neutron capture therapy; boronic acid; hydroboration; sugar analogue
  • , where, among other derivatives, 1,2-dideoxy-ᴅ-glucopyranos-2-ylboronic acid has been synthesized through a regio- and stereoselective hydroboration of persilylated glucal. Considering the different substitution positions for the boronic acid in the sugar skeleton, we were curious to observe the chemical
  • the 2,3-dideoxy derivatives, whose structures are reported in Figure 2, in order to have a reliable synthesis and to get preliminary information on their stability. We planned a strategy based on a hydroboration reaction of terminal, suitably functionalized alkenes, which can be obtained from properly
PDF
Album
Supp Info
Full Research Paper
Published 19 Jun 2019

Stereo- and regioselective hydroboration of 1-exo-methylene pyranoses: discovery of aryltriazolylmethyl C-galactopyranosides as selective galectin-1 inhibitors

  • Alexander Dahlqvist,
  • Axel Furevi,
  • Niklas Warlin,
  • Hakon Leffler and
  • Ulf J. Nilsson

Beilstein J. Org. Chem. 2019, 15, 1046–1060, doi:10.3762/bjoc.15.102

Graphical Abstract
  • using a highly diastereoselective hydroboration of C1-exo-methylene pyranosides giving inhibitors with fourfold or better selectivity for galectin-1 over galectin-3, -4C (C-terminal CRD), -4N (N-terminal CRD), -7, -8C, -8N, -9C, and -9N and dissociation constants down to 170 µM. Keywords: C-galactoside
  • ; galectin-1; hydroboration; inhibition; selective; triazole; Introduction Galectins are defined by a typically about 130 amino acid carbohydrate recognition domain (CRD) that binds to carbohydrates with at least one β-galactose subunit within a binding pocket large enough to accommodate a tetrasaccharide
  • synthesis pathway involving a diastereoselective hydroboration towards (aryltriazolyl)methyl galactopyranosyl derivatives and determined the viability of this as a scaffold for galectin inhibitors by screening a library of fourteen different products against galectins -1, -3, -4C (C-terminal CRD), -4N (N
PDF
Album
Supp Info
Full Research Paper
Published 07 May 2019

An efficient synthesis of the guaiane sesquiterpene (−)-isoguaiene by domino metathesis

  • Yuzhou Wang,
  • Ahmed F. Darweesh,
  • Patrick Zimdars and
  • Peter Metz

Beilstein J. Org. Chem. 2019, 15, 858–862, doi:10.3762/bjoc.15.83

Graphical Abstract
  • of the aldehyde function as the dimethyl acetal [16][17][18], hydroboration and oxidative work-up of 10 provided a mixture of epimeric alcohols 11 that was unified by Ley–Griffith oxidation [19] to give ketone 12 [20]. Subsequent Wittig reaction with ylide 13 and acetal cleavage of the resultant
PDF
Album
Supp Info
Full Research Paper
Published 09 Apr 2019

The chemistry and biology of mycolactones

  • Matthias Gehringer and
  • Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

Graphical Abstract
PDF
Album
Review
Published 11 Aug 2017

Transition-metal-free one-pot synthesis of alkynyl selenides from terminal alkynes under aerobic and sustainable conditions

  • Adrián A. Heredia and
  • Alicia B. Peñéñory

Beilstein J. Org. Chem. 2017, 13, 910–918, doi:10.3762/bjoc.13.92

Graphical Abstract
  • applications of alkynyl selenides are electrophilic addition reactions, many of them modulated by transition-metal catalysts [11]. Some examples are: hydroboration which results in a vinylborane selenide used in Pd-catalyzed Suzuki cross-coupling reactions [12], the addition to tributyltin hydride in the
PDF
Album
Supp Info
Full Research Paper
Published 16 May 2017

Studies directed toward the exploitation of vicinal diols in the synthesis of (+)-nebivolol intermediates

  • Runjun Devi and
  • Sajal Kumar Das

Beilstein J. Org. Chem. 2017, 13, 571–578, doi:10.3762/bjoc.13.56

Graphical Abstract
  • intermediates, we first needed to synthesize the syn-dihydroxy esters 19 and 20 (Scheme 4). Toward that objective, 2-allyl-4-fluorophenol (15) was benzylated with BnCl and anhydrous K2CO3 in the presence of KI in acetone under reflux conditions to obtain benzyl ether 16 (Scheme 4). The subsequent hydroboration
PDF
Album
Supp Info
Letter
Published 21 Mar 2017

The reductive decyanation reaction: an overview and recent developments

  • Jean-Marc R. Mattalia

Beilstein J. Org. Chem. 2017, 13, 267–284, doi:10.3762/bjoc.13.30

Graphical Abstract
  • protocol is successfully used with various electron-deficient substituted phenyl groups (15b–e) and with heterocycles (15f–h). The double-bond of cyanopyrrolidine 14l is preserved from the hydroboration reaction (15l). Olefins bearing bulky ester, sulfone or amide groups afforded good to excellent yields
PDF
Album
Review
Published 13 Feb 2017

Diastereoselective synthesis of new O-alkylated and C-branched inositols and their corresponding fluoro analogues

  • Charlotte Collet,
  • Françoise Chrétien,
  • Yves Chapleur and
  • Sandrine Lamandé-Langle

Beilstein J. Org. Chem. 2016, 12, 353–361, doi:10.3762/bjoc.12.39

Graphical Abstract
  • bromide under classical conditions in the presence of NaH at reflux [44] to afford myo-9 and scyllo-9 in good yield of 80% and 82%, respectively. The hydroxylated arm was obtained by hydroboration using BH3 on the unsaturated compounds myo-9 and scyllo-9 followed by an oxidation with H2O2/NaOH allowing
  • , after hydroboration using BH3 in THF at 0 °C followed by conventional oxidation using H2O2/NaOH, in 70–80% yield. Subsequent catalytic hydrogenation under pressure with Pd(OH)2 as the catalyst [45] allowed to obtaining quantitatively the fully hydroxylated inositols myo-3, scyllo-3, myo-4 and scyllo-4
PDF
Album
Supp Info
Full Research Paper
Published 25 Feb 2016

Copper-catalyzed stereoselective conjugate addition of alkylboranes to alkynoates

  • Takamichi Wakamatsu,
  • Kazunori Nagao,
  • Hirohisa Ohmiya and
  • Masaya Sawamura

Beilstein J. Org. Chem. 2015, 11, 2444–2450, doi:10.3762/bjoc.11.265

Graphical Abstract
  • Takamichi Wakamatsu Kazunori Nagao Hirohisa Ohmiya Masaya Sawamura Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan 10.3762/bjoc.11.265 Abstract A copper-catalyzed conjugate addition of alkylboron compounds (alkyl-9-BBN, prepared by hydroboration of
  • mode. The syn stereoselectivity was excellent regardless of the substrate structure, and a variety of functional groups were tolerated in both the alkylborane and the alkynoate. Results and Discussion Alkylborane 2a (0.275 mmol), which was obtained via hydroboration of styrene (1a) with the 9
  • accessible through the hydroboration–conjugate addition one-pot protocol with excellent syn stereoselectivities (Table 2). This protocol tolerated functional groups such as methoxy, ester, phthalimide, fluoro, cyano and aldehyde moieties in the alkylboranes and alkynoates (Table 2, entries 1–3, 6–9 and 11
PDF
Album
Supp Info
Full Research Paper
Published 04 Dec 2015

Selected synthetic strategies to cyclophanes

  • Sambasivarao Kotha,
  • Mukesh E. Shirbhate and
  • Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

Graphical Abstract
  • –Miyaura coupling: Bodwell and Li [127] have reported the synthesis of the cyclophane 130 involving hydroboration and the Suzuki–Miyaura (SM) coupling [128][129][130][131][132][133][134][135] as key steps. 1,3-Diallylindole (127) was first synthesized in two steps from indole (123) by successive allylation
PDF
Album
Review
Published 29 Jul 2015

Novel stereocontrolled syntheses of tashiromine and epitashiromine

  • Loránd Kiss,
  • Enikő Forró and
  • Ferenc Fülöp

Beilstein J. Org. Chem. 2015, 11, 596–603, doi:10.3762/bjoc.11.66

Graphical Abstract
  • –cyclization [27], or electrophilic pyrolidinone alkylation followed by ring closure [28][29]. Pyrrolidine alkylation and nucleophilic ring closure followed by C–C double bond hydroboration [30] leads to racemic epitashiromine, as does the N-alkylated succinimide transformation through the corresponding
PDF
Album
Full Research Paper
Published 30 Apr 2015

Formal total syntheses of classic natural product target molecules via palladium-catalyzed enantioselective alkylation

  • Yiyang Liu,
  • Marc Liniger,
  • Ryan M. McFadden,
  • Jenny L. Roizen,
  • Jacquie Malette,
  • Corey M. Reeves,
  • Douglas C. Behenna,
  • Masaki Seto,
  • Jimin Kim,
  • Justin T. Mohr,
  • Scott C. Virgil and
  • Brian M. Stoltz

Beilstein J. Org. Chem. 2014, 10, 2501–2512, doi:10.3762/bjoc.10.261

Graphical Abstract
  • ), giving allyl ketone (−)-18 in 94% yield and 91% ee [34]. Treatment of the ketone (−)-18 with MeMgBr at 23 ºC provided a mixture of two diastereomeric alcohols 19A and 19B in 94% yield. Without separation, the diastereomers were rapidly carried through a three-step sequence of hydroboration/oxidation
PDF
Album
Supp Info
Full Research Paper
Published 28 Oct 2014

Olefin cross metathesis based de novo synthesis of a partially protected L-amicetose and a fully protected L-cinerulose derivative

  • Bernd Schmidt and
  • Sylvia Hauke

Beilstein J. Org. Chem. 2014, 10, 1023–1031, doi:10.3762/bjoc.10.102

Graphical Abstract
  • perdeuteration of an alkynoate derived from L-threonine (giving a 2,2,3,3-tetradeuterated amicetose) [26], enantioselective hydroboration of hetero Diels–Alder adducts [27], stereoconservative diazotation of L-glutamic acid [28][29], diastereoselective addition of methylmagnesium bromide to enantiopure 2
PDF
Album
Supp Info
Full Research Paper
Published 06 May 2014

Addition of H-phosphonates to quinine-derived carbonyl compounds. An unexpected C9 phosphonate–phosphate rearrangement and tandem intramolecular piperidine elimination

  • Łukasz Górecki,
  • Artur Mucha and
  • Paweł Kafarski

Beilstein J. Org. Chem. 2014, 10, 883–889, doi:10.3762/bjoc.10.85

Graphical Abstract
  • (R/S). The homologous aldehyde can be prepared by oxidation of the double bond in a hydroboration–oxidation sequence, however, the presence of the nitrogen atoms, particularly that of the tertiary amino group of quinuclidine, may be troubleshooting [28][29]. Borane complexes with heteroaromatic and
  • aliphatic amines are considered inconveniently stable in protic solvents (water, alcohols) and dissociate only at an elevated temperature [30]. Most probably, in our case the formation of the amine–borane complex proceeded faster than the hydroboration of the vinyl group. When compound 2 was reacted with
  • complexed forms (borane-tertiary amino group). Again, step-by-step approach and separation of the intermediate appeared more profitable. First, the alcohol 7 was synthesized by hydroboration of the substrate with BH3·THF under an inert atmosphere followed by oxidation of the intermediate borane 5 complex
PDF
Album
Supp Info
Full Research Paper
Published 17 Apr 2014

Direct and indirect single electron transfer (SET)-photochemical approaches for the preparation of novel phthalimide and naphthalimide-based lariat-type crown ethers

  • Dae Won Cho,
  • Patrick S. Mariano and
  • Ung Chan Yoon

Beilstein J. Org. Chem. 2014, 10, 514–527, doi:10.3762/bjoc.10.47

Graphical Abstract
  • into the amidols 69 can be easily achieved by employing Lewis acid-catalyzed reactions with allyltrimethylsilane, which produce the allylation products 71. Hydroboration–oxidation of the terminal olefin moieties in 71 then forms the corresponding alcohols 70 that contain key hydroxypropyl side chains
PDF
Album
Review
Published 27 Feb 2014

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

  • Sebastian Krüger and
  • Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

Graphical Abstract
  • synthesis of the diterpene scopadulcic acid B (79, see Scheme 10), isolated from the Paraguayan plant Scoparia dulcis [66]. Starting from 2-iodobenzaldehyde (65) allyl-Grignard addition took place followed by TBS-protection of the resulting alcohol. The installed double bond was subjected to hydroboration
  • yielded intermediate cis-divinylcyclopropane 164, which underwent the desired rearrangement at remarkably low temperature to yield bicycle 165. Selective hydroboration/oxidation (directed through participation of the untouched double bond) followed by Swern oxidation gave ketone 166. The enone system 167
  • was prepared through addition of Eschenmoser’s salt, followed by Hoffman elimination of the resulting amine. Luche reduction [143] from the less hindered side followed by hydroboration/oxidation gave diol 168. Mono-mesylation of the primary alcohol followed by the addition of base furnished the
PDF
Album
Review
Published 16 Jan 2014
Graphical Abstract
  • ). With borane–dimethylsulfide complex as the reductant and 10 mol % of catalyst, no conversion was observed at −78 °C (Table 3, entry 1), whereas attempted reduction at ambient temperature (Table 3, entry 2) resulted in the formation of a complex mixture, presumably due to competing hydroboration of the
PDF
Album
Supp Info
Full Research Paper
Published 18 Nov 2013

Cyclopamine analogs bearing exocyclic methylenes are highly potent and acid-stable inhibitors of hedgehog signaling

  • Johann Moschner,
  • Anna Chentsova,
  • Nicole Eilert,
  • Irene Rovardi,
  • Philipp Heretsch and
  • Athanassios Giannis

Beilstein J. Org. Chem. 2013, 9, 2328–2335, doi:10.3762/bjoc.9.267

Graphical Abstract
  • , 0 °C, 93%), (2) hydroboration/oxidation (9-BBN, THF, 70 °C; then NaBO3, H2O, 50 °C, 91%) and finally, (3) oxidative cyclization (BAIB, cat. TEMPO, CH2Cl2, 25 °C, 73%) was employed. Deprotection of the silyl ether (HF, MeCN, 25 °C, 87%) and base-induced rearrangement of the steroid skeleton via the
PDF
Album
Supp Info
Full Research Paper
Published 31 Oct 2013

Amyloid-β probes: Review of structure–activity and brain-kinetics relationships

  • Todd J. Eckroat,
  • Abdelrahman S. Mayhoub and
  • Sylvie Garneau-Tsodikova

Beilstein J. Org. Chem. 2013, 9, 1012–1044, doi:10.3762/bjoc.9.116

Graphical Abstract
  • imidazopyridine, [18F]FPPIP (142), was prepared starting from 140e. A palladium-catalyzed coupling with tributyl(vinyl)tin to give an alkene intermediate was followed by hydroboration-oxidation to give the hydroxypropyl intermediate 145, which was radiolabeled to give 142 (Scheme 10B). This compound showed good
PDF
Album
Review
Published 28 May 2013

Methylidynetrisphosphonates: Promising C1 building block for the design of phosphate mimetics

  • Vadim D. Romanenko and
  • Valery P. Kukhar

Beilstein J. Org. Chem. 2013, 9, 991–1001, doi:10.3762/bjoc.9.114

Graphical Abstract
  • reasonable yield, but the 1-allyl-substituted trisphosphonate 12b did not undergo hydroboration with 9-BBN. However, treatment of 12b with borane in THF resulted in conversion to the primary alcohol 34 in good yield (Scheme 16) [26]. A further example of the reactivity of trisphosphonates is provided by a
  • . Reaction between tert-butylphosphaethyne and diethyl phosphite in the presence of sodium metal. Cross metathesis of trisphosphonates 12 with 2-methyl-2-butene and the Grubbs second-generation catalyst. Hydroboration–oxidation of trisphosphonates 12b,e. Reaction of 3-butyn-1-ylidenetrisphosphonate 15 with
PDF
Album
Review
Published 24 May 2013

The chemistry of bisallenes

  • Henning Hopf and
  • Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

Graphical Abstract
PDF
Album
Review
Published 15 Nov 2012
Other Beilstein-Institut Open Science Activities