Catalytic Enantioselective Alkynylation of Trifluoromethyl Ketones: Pronounced Metal Fluoride Effects and Implications of Zinc-to-Titanium Transmetallation
作者:Guang-Wu Zhang、Wei Meng、Hai Ma、Jing Nie、Wen-Qin Zhang、Jun-An Ma
DOI:10.1002/anie.201007341
日期:2011.4.4
(L1 and L2), was developed for the synthesis of both enantiomers of trifluoromethylated propargylic tertiary alcohols in high yield and enantioselectivity. Small amounts of BaF2 were found to be essential for maintaining high levels of reactivity and enantioselectivity.
Enantioselective alkynylation of trifluoromethyl ketones catalyzed by chiral Schiff bases in the presence of Me2Zn afforded the corresponding trifluoroalkynyl alcohols in up to 66 % ee.
Enantioselective Alkynylation of Trifluoromethyl Ketones Catalyzed by Cation‐Binding Salen Nickel Complexes
作者:Dongseong Park、Carina I. Jette、Jiyun Kim、Woo‐Ok Jung、Yongmin Lee、Jongwoo Park、Seungyoon Kang、Min Su Han、Brian M. Stoltz、Sukwon Hong
DOI:10.1002/anie.201913057
日期:2020.1.7
Cation-binding salen nickel catalysts were developed for the enantioselective alkynylation of trifluoromethyl ketones in high yield (up to 99 %) and high enantioselectivity (up to 97 % ee). The reaction proceeds with substoichiometric quantities of base (10-20 mol % KOt-Bu) and open to air. In the case of trifluoromethyl vinyl ketones, excellent chemo-selectivity was observed, generating 1,2-addition