1196458-79-3Relevant academic research and scientific papers
Asymmetric synthesis of γ-hydroxy-α,β-acetylenic esters catalyzed by oxazolidine-titanium complex
Mao, Jincheng,Guo, Jun
experimental part, p. 2295 - 2300 (2009/12/08)
An efficient catalytic system has been developed for the enantioselective reaction of alkynoates with aromatic aldehydes for the synthesis of optically active γ-hydroxy-α,β-acetylenic esters (with up to 81% isolated yield and up to 84% enantioselectivity)
3,3′-anisyl-substituted BINOL, H4BINOL, and H 8BINOL ligands: Asymmetric synthesis of diverse propargylic alcohols and their ring-closing metathesis to chiral cycloalkenes
Yue, Yang,Turlington, Mark,Yu, Xiao-Qi,Pu, Lin
supporting information; experimental part, p. 8681 - 8689 (2009/12/30)
(Chemical Equation Presented) A series of optically active BINOL, H 4BINOL, and H8BINOL derivatives were prepared. These compounds in combination with ZnEt2 and Ti(OiPr) 4 were used to catalyze the asymmetric reaction of alkynes with aldehydes to generate chiral propargylic alcohols at room temperature. Through this comparative study, a 3,3′-bisanisyl-substituted H8BINOL (S)-7 was found to be a generally enantioselective catalyst for the reaction of structurally diverse terminal alkynes with a variety of aldehydes. It catalyzed the reactions of alkyl propiolates with 88-99% ee; the reactions of phenylacetylene with 81-87% ee; the reactions of 4-phenyl-1-butyne, an alkyl alkyne, with 77-89% ee; and the reactions of trimethylsilylacetylene with 92-97% ee. The optically active propargylic alcohols generated from this catalytic asymmetric alkyne addition were observed to undergo efficient ring-closing-metathesis (RCM) reaction in the presence of the Grubbs II catalyst to produce chiral cycloalkenes. It was further found that some of the chiral propargylic alcohols underwent a highly chemoselective tandem RCM hydrogenation reaction with retention of the enantiomeric purity. 2009 American Chemical Society.
