Mg(OMe)<sub>2</sub> promoted allylic isomerization of γ-hydroxy-α,β-alkenoic esters to synthesize γ-ketone esters
作者:Luhao Lai、A-Ni Li、Jiawei Zhou、Yarong Guo、Li Lin、Wei Chen、Rui Wang
DOI:10.1039/c7ob00131b
日期:——
This work concerns the Mg(OMe)2 promoted allylic isomerization of γ-hydroxy-α,β-alkenoic esters with TMEDA as an additive. The isomerization proceeded under mild conditions and afforded γ-keto esters in high yield (up to 96%) within 2 h. Both (Z)- and (E)-γ-hydroxy-α,β-alkenoic esters were tolerated under the reaction conditions. This transformation involves the in situ formation of a dienolate intermediate
Sodium Bicarbonate-Catalyzed Stereoselective Isomerizations of Electron-Deficient Propargylic Alcohols to (<i>Z</i>)-Enones
作者:John P. Sonye、Kazunori Koide
DOI:10.1021/jo0623944
日期:2007.3.1
Redoxisomerization is a synthetically important process because it creates two new functional groups in the product, among which is the isomerization of propargylic alcohols to conjugated enones. Although E-enones have been prepared by this approach, Z-enones could not be accessed. We previously reported DABCO-catalyzed E-selective isomerization of electron-deficient propargylic alcohols to enones
Cyclic acetal formation between 2-pyridinecarboxyaldehyde and γ-hydroxy-α,β-acetylenic esters
作者:Sami Osman、Kazunori Koide
DOI:10.1016/j.tetlet.2008.09.008
日期:2008.11
A new transformation between 2-pyridinecarboxyaldehyde and gamma-hydroxy-alpha,beta-acetylenic esters to form highly functionalized cyclicacetals was discovered. This transformation proceeds under very mild conditions without any additives and is promoted by the basic nature of the pyridine ring.
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.
Robust eco-friendly protocol for the preparation of γ-hydroxy-α,β-acetylenic esters by sequential one-pot elimination–addition of 2-bromoacrylates to aldehydes promoted by LTMP in 2-MeTHF
作者:Vittorio Pace、Laura Castoldi、Andrés R. Alcántara、Wolfgang Holzer
DOI:10.1039/c2gc35305a
日期:——
An efficient and widely applicable preparation of γ-hydroxy-α,β-acetylenicesters is described by means of a one-pot dehydrobromination of a 2-bromoacrylate ester with LTMP followed by the electrophilic addition of the transient propiolate to different aldehydes in the eco-friendly solvent 2-MeTHF.