The borrowing-hydrogen (or hydrogen autotransfer) process, where the catalyst dehydrogenates a substrate and formally transfers the H atom to an unsaturated intermediate, is an atom-efficient and environmentally benign transformation. Described here is an example of an asymmetric borrowing-hydrogen cascade for the formal anti-Markovnikov hydroamination of allyl alcohols to synthesize optically enriched
A direct route to branched N-allylpyrimidine analogues is herein reported via the highly regio- and enantioselective asymmetricallylation of pyrimidines with racemic allylic carbonates. With [Rh(COD)Cl]2/chiral diphosphine as the catalyst, a range of chiral pyrimidine acyclic nucleosides could be obtained under neutral conditions in good yields (up to 95% yield) with high levels of regio- and enantioselectivities
Anti‐Markovnikov Hydroamination of Racemic Allylic Alcohols to Access Chiral γ‐Amino Alcohols
作者:Ruirui Xu、Kun Wang、Haoying Liu、Weijun Tang、Huaming Sun、Dong Xue、Jianliang Xiao、Chao Wang
DOI:10.1002/anie.202009754
日期:2020.12
ruthenium‐catalyzed formal anti‐Markovnikov hydroamination of allylicalcohols for the synthesis of chiral γ‐amino alcohols is presented. Proceeding via an asymmetric hydrogen‐borrowing process, the catalysis allows racemic secondary allylicalcohols to react with various amines, affording enantiomerically enriched chiral γ‐amino alcohols with broad substrate scope and excellent enantioselectivities (68 examples
Rh-Catalyzed Regioselective Dialkylation of Cage B–H bonds in o-Carboranes: Oxidative Heck Reactions via an Enol Isomerization
作者:Qian Wang、Song Tian、Chuyi Zhang、Jiangwei Li、Zhixuan Wang、Yongmei Du、Ling Zhou、Jian Lu
DOI:10.1021/acs.orglett.9b03009
日期:2019.10.4
In the presence of a carboxylic acid directing group, Rh-catalyzed regioselective directed dialkylation of B(4,5)-H bonds in o-carboranes and oxidative coupling with allylic alcohols is reported. This strategy constructs a series of 4,5-dialkylated o-carboranes in good yields with excellent regioselectivity. A possible catalytic cycle is proposed that involves a tandem sequence of Rh-catalyzed cage
Asymmetric Allylic Alkylation of β-Ketoesters with Allylic Alcohols by a Nickel/Diphosphine Catalyst
作者:Yusuke Kita、Rahul D. Kavthe、Hiroaki Oda、Kazushi Mashima
DOI:10.1002/anie.201508757
日期:2016.1.18
Asymmetricallylicalkylation of β‐ketoesters with allylicalcohols catalyzed by [Ni(cod)2]/(S)‐H8‐BINAP was found to be a superior synthetic protocol for constructing quaternary chiral centers at the α‐position of β‐ketoesters. The reaction proceeded in high yield and with high enantioselectivity using various β‐ketoesters and allylicalcohols, without any additional activators. The versatility of