[GRAPHICS]Additions of terminal alkynes to electrophiles are important transformations in organic chemistry. Generally, activated terminal alkynes react with epoxides in an S(N)2 fashion to form homopropargylic alcohols. We have developed a new synthetic method to form propargylic alcohols from epoxides and terminal alkynes via 1,2-shifts. This method involves cationic zirconium acetylides as both the activator of epoxides and nucleophiles. line to the mild conditions to pre-activate alkynes with silver nitrate, this synthetic method is useful for both electron-rich and electron-deficient alkynes with other acid- and base-sensitive functional groups.
Base-Catalyzed Highly Stereoselective Conversion of γ-Hydroxy-α,β-acetylenic Esters to γ-Acetoxy Dienoates
作者:Yang Yue、Xiao-Qi Yu、Lin Pu
DOI:10.1002/chem.200802355
日期:2009.5.11
A convenient route with high stereo control to γ‐acetoxy dienoates is provided by the reaction of methyl propiolate with aldehydes in the presence of ZnEt2 and N‐methylimidazole at room temperature, followed by the catalytic conversion of the resulting γ‐hydroxy‐α,β‐acetylenic esters with p‐N,N‐dimethylaminopyridine (DMAP) in acetic anhydride (see scheme).
A Mild Method for the Preparation ofγ-Hydroxy-α,β-Acetylenic Esters
作者:Shatrughan P. Shahi、Kazunori Koide
DOI:10.1002/anie.200353400
日期:2004.5.3
Highly enantioselective catalytic methyl propiolate addition to both aromatic and aliphatic aldehydes
作者:Jian Huang、Siping Wei、Li Wang、Chun Zhang、Shuangxun Li、Pingxian Liu、Xi Du、Qin Wang
DOI:10.1016/j.tetasy.2016.03.009
日期:2016.6
The excellent catalytic effect on methyl propiolate addition to a wide range of aromatic and aliphatic aldehydes promoted by inexpensive and commercially available BINOL-based ligand is reported. The catalyst systems showed high yields and excellent enantioselectivities for aromatic aldehydes, and excellent yields and high enantioselectivities for aliphatic aldehydes. (C) 2016 Elsevier Ltd. All rights reserved.