CBS Oxazaborolidines - Versatile Catalysts for Asymmetric Synthesis

Stemmler, René T.

doi:10.1055/s-2007-973876

Cited by 15 publications

(6 citation statements)

References 8 publications

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“…The hydroformylation products of cyclic alkenes, such as N -Boc-2,3-dihydropyrrole and 2,3- and 2,5-dihydrofurans are useful precursors and intermediates in organic synthesis. − This substrate class has remained challenging − and was evaluated (Table ) with ligands 1 – 8 . Hydroformylation of N -Boc-2,3-dihydropyrrole shows preference for the α-aldehyde (because only branched products are possible for these disubstituted alkenes, the regioisomeric products are labeled as α and β with respect to the heteroatom) product with all tested ligands.…”

Section: Resultsmentioning

confidence: 99%

Backbone-Modified Bisdiazaphospholanes for Regioselective Rhodium-Catalyzed Hydroformylation of Alkenes

2017

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A series of tetraaryl bisdiazaphospholane (BDP) ligands were prepared varying the phosphine bridge, backbone, and substituents in the 2-and 5-positions of the diazaphospholane ring. The parent acylhydrazine backbone was transformed to an alkylhydrazine via a borane reduction procedure. These reduced ligands contained an all sp 3 hybridized ring mimicking the all sp 3 phospholane of (R,R)-Ph-BPE, a highly selective ligand in asymmetric hydroformylation. The reduced bisdiazaphospholane (red-BDP) ligands were shown crystallographically to have an increased C−N−N−C torsion anglethis puckering resembles the structure of (R,R)-Ph-BPE and has a dramatic influence on regioselectivity in rhodium catalyzed hydroformylation. The red-BDPs demonstrated up to a 5-fold increase in selectivity for the branched aldehyde compared to the acylhydrazine parent ligands. This work demonstrates a facile procedure for increased branched selectivity from the highly active and accessible class of BDP ligands in hydroformylation.

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Section: Resultsmentioning

confidence: 99%

Backbone-Modified Bisdiazaphospholanes for Regioselective Rhodium-Catalyzed Hydroformylation of Alkenes

2017

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“…Boronic acids and their derivatives have also found application in other reaction classes through modes of activation similar to those described above. Perhaps the most widely known organoboron derivatives in catalysis are the oxazaborolidine catalysts used in the Corey–Bakshi–Shibata reduction, which can induce asymmetry. − These catalysts, which are easily accessed by the condensation of arylboronic acids and amino alcohols, can provide versatile systems for asymmetric catalysis. Here, we focus on lesser known examples of catalysis by organoboron acids of other reaction classes, specifically, epoxide ring-opening, aziridination, chemoselective oxidation and reduction, CO 2 activation, silylation, reactions with alkenes and alkynes, and C–H activation.…”

Section: Other Reactivitymentioning

confidence: 99%

Emergent Organoboron Acid Catalysts

Graham

Raines

2022

J. Org. Chem.

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Organoboron acids are stable, organic-soluble Lewis acids with potential application as catalysts for a wide variety of chemical reactions. In this review, we summarize the utility of boronic and borinic acids, as well as boric acid, as catalysts for organic transformations. Typically, the catalytic processes exploit the Lewis acidity of trivalent boron, enabling the reversible formation of a covalent bond with oxygen. Our focus is on recent developments in the catalysis of dehydration, carbonyl condensation, acylation, alkylation, and cycloaddition reactions. We conclude that organoboron acids have a highly favorable prospectus as the source of new catalysts.

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“…此外, 基于面手性的二茂铁骨架 [18] 以及环戊二烯-铼络合物 [19] 衍生的膦烯烃配体也被合成出来, 如配体 33 和 34, 但是其诱导催化不对称反应的效果不是很理想, 在芳基硼酸对 2-环己烯酮的加成反应中可以得到中等到较好的对映选择性.…”

Section: Chineseunclassified

Application of Chiral Olefin Ligands in Asymmetric Catalysis

Feng¹,

Du²

2015

Chin. J. Org. Chem.

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As a novel class of potential ligands, chiral olefin ligands have attracted much attention. Chiral olefin ligands exhibit higher activity and selectivity than the traditional nitrogen, phosphine, oxide ligands in some reactions, and solved some problems that other ligands could not do. To enhance the coordination of the olefin ligands and the metal, heteroatoms were introduced to its backbone, several hybrid olefin ligands have been developed to increase the diversity of the ligands for further expanding the application of chiral olefin ligands. In this review, the recent advances in the development of chiral diene ligands, chiral phosphine olefin ligands and chiral sulfur olefin ligands, and their application in transition-metal catalyzed asymmetric reactions are reviewed. Keywords chiral olefin ligand; asymmetric catalysis; chiral diene ligand; chiral P/alkene ligand; chiral S/alkene ligand2, 在铱催化的烯丙基碳酸酯的动力学拆分反应中也得到了优秀的结果. 从此手性烯烃配体的开发引起了化学家们的重视, 围绕着不对称催化而设计的手性烯烃配体陆续出现, 在诱导不对称催化反应中取得很好的效果. 这些手性双烯配体在有些反应中甚至表现出比传统氮、磷、氧配体更高的活性和选择性, 实现了一些利用其它类型配体难以实现的化学转化, 由此可见, 手性烯烃配体是一类具有重要应用前景的新型配体. 林国强院士在这一领域也做出了突出的贡献. 2007 年, 林国强小组 [4a] 报道了新型的 C 2 对称的手性[3.3.0]环戊二烯骨架的双烯配体

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CBS Oxazaborolidines - Versatile Catalysts for Asymmetric Synthesis

Abstract: This feature focuses on a reagent chosen by a postgraduate, highlighting the uses and preparation of the reagent in current research

Cited by 15 publications

References 8 publications

Backbone-Modified Bisdiazaphospholanes for Regioselective Rhodium-Catalyzed Hydroformylation of Alkenes

Backbone-Modified Bisdiazaphospholanes for Regioselective Rhodium-Catalyzed Hydroformylation of Alkenes

Emergent Organoboron Acid Catalysts

Application of Chiral Olefin Ligands in Asymmetric Catalysis

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