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
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.
Meerwein-Ponndorf-Verley-type reduction of N-tosylsilylimines with chiral lithium amide 2 affords alpha-silylamines in high enantioselectivity. Since the enantioselectivity observed was inconsistent with our previously proposed chairlike six-membered transition structure, we performed density functional theory (DFT) calculations on transition states leading to (S)- and (R)-7a and (S)- and (R)-7e using an N-phenylsulfonyl derivatives 12 and 13 as model systems. Results of the calculations showed that the structures are considerably deformed from the chairlike form with steric repulsions between the 1'-methylene group and the imine-carbon substituents playing an important role in the control of the, enantioselectivity.