Enantioselective synthesis of synthetically significant (α‐hydroxyallyl)silanes, (α‐hydroxyaryl)silanes, and (α‐hydroxyalkyl)silanes is reported. The present copper‐catalyzed 1,2‐selective hydroborylation of acylsilanes affords the aforementioned products in high yields and with high enantiomeric excesses. This robust and scalable additive‐free catalytic system relies on the use of low copper(II) acetate
The synthesis of various types of optically active α-(allenylsilane-containing)glycines via a chirality-transferring ester-enolate Claisen rearrangement of α-acyloxy-α-alkynylsilanes is described. The conversion of the rearranged products into the optically active silicon-free α-(allenyl)- and α-substituted-α-(allenyl)glycines was achieved by the removal of the Me2PhSi- or TMS group from the allene
Enantioconvergent and Regioselective Synthesis of Allenylsilanes by Nickel-Catalyzed C(sp<sup>2</sup>)–C(sp<sup>3</sup>) Cross-Coupling Starting from Racemic α-Silylated Propargylic Bromides
作者:Yan Xu、Hong Yi、Martin Oestreich
DOI:10.1021/acs.organomet.1c00112
日期:2021.7.26
A direct synthesis of enantioenriched allenylsilanes fromracemic α-silylated propargylic bromides by an enantioconvergent nickel-catalyzed cross-coupling is reported. The high regioselectivity is governed by the bulky silyl group, and the C(sp2)–C(sp3) bond formation occurs exclusively at the γ-position of the propargyl electrophile. The level of enantioselection induced by a chiral Pybox ligand is
Nucleophilic Allylation of Acylsilanes in Water: An Effective Alternative to Functionalized Tertiary α-Silylalcohols
作者:Xiu-Xia Liang、Chen Zhu、Wang Zhang、Ya-Nan Du、Lei Xu、Lihua Liu、Yicheng Zhang、Man-Yi Han
DOI:10.1021/acs.joc.3c00668
日期:2023.8.18
nucleophilic allylation of acylsilanes in water was developed, generating versatile functionalized tertiary α-silyl alcohols in high yields. With the assistance of hydrogen bonding, a reaction model of less reactive acylsilane was achieved. Unlike the conventional strategy, transition metals and an additional Lewis acid catalyst were not required, and rate acceleration was observed in water.
The Au(I)-catalyzed cyclization of an allenylglycine, which possessed a silyl group attached to the opposite side of the allenic terminus, occurred at the allenic center to produce the 2-amino-4-silylmethylene-substituted gamma-butyrolactone 2a in a highly regio- and stereoselective manner. The presence of a silyl group at the allenic terminus is crucial for the present 5-endo-dig gamma-butyrolactonization. (C) 2011 Elsevier Ltd. All rights reserved.