Asymmetric Guerbet Reaction to Access Chiral Alcohols
作者:Kun Wang、Lin Zhang、Weijun Tang、Huaming Sun、Dong Xue、Ming Lei、Jianliang Xiao、Chao Wang
DOI:10.1002/anie.202003104
日期:2020.7.6
example of an asymmetric Guerbet reaction has been developed. Using commercially available, classic Noyori RuII‐diamine‐diphosphine catalysts, well‐known in asymmetric hydrogenation, racemic secondary alcohols are shown to couple with primary alcohols in the presence of a base, affording new chiral alcohols with enantiomeric ratios of up to 99:1. Requiring no reducing agents, the protocol provides an easy
Efficient Iron-Catalyzed Direct β-Alkylation of Secondary Alcohols with Primary Alcohols
作者:Jian Yang、Xin Liu、Da-Li Meng、Hong-Yan Chen、Zhi-Hui Zong、Ting-Ting Feng、Kai Sun
DOI:10.1002/adsc.201000907
日期:2012.2
β-alkylation of secondary alcohols with primaryalcohols is described. In the presence of the commerciallyavailable iron catalyst (ferrocenecarboxaldehyde, 1b) and a catalytic amount of base, the reactions give β-alkylated higher alcohols in high yields in the absence of any sacrificial agents (hydrogen acceptors or hydrogen donors) and nitrogen or phosphorus ligands. For the firsttime, iron is employed
A simple base, KOH-catalyzed cross-coupling of primary and secondaryalcohols is reported in which the primaryalcohols play the role of alkylation reagents. EPR and mechanistic studies confirmed the involvement of radical and ketone intermediates formed from primary and secondaryalcohols, respectively, leading to the formation of β-alkylated secondaryalcohols. Graphical abstract A simple base-catalyzed