Alkali metal hydride or aqueous hydroxide induced conjugate addition of trimethylsilyl enol ethers to enones. A convenient alternative to Lewis acid mediated reaction
作者:Vishwanath M. Swamy、Amitabha Sarkar
DOI:10.1016/s0040-4039(97)10771-7
日期:1998.3
Conjugate addition to enones by enolates derived from base-induced cleavage of OSi bond of trimethylsilyl enol ethers, yields 1,5-dicarbonyl compounds in good yields.
An efficient and improved synthesis of 1,5-diketones: versatile conjugate addition of nucleophiles to α,β-unsaturated enones and alkynones
作者:Ravi Shankar、Ashok K. Jha、Uma Sharan Singh、K. Hajela
DOI:10.1016/j.tetlet.2006.03.008
日期:2006.5
Several 1,5-diketones have been prepared in good to excellent yields by versatile conjugate addition of nucleophiles such as cyclic or acyclic ketones, amines and thiols to α,β-unsaturated enones and alkynones, in the presence of catalytic amounts of 10% aq NaOH, TBAI and DMSO at ambient temperature. The choice of solvent and phase-transfer catalyst played a critical role in improving the reaction
A tandem cross-coupling reaction of aryl methyl ketones with aromatic aldehydes has been accomplished employing barium isopropoxide as a catalyst, in which barium enolates are generated and then three consecutive reactions (aldol reaction/beta-elimination/conjugate addition) occur; this one- pot procedure is a convenient method to obtain symmetrical 1,5-diketones in good yields. In some cases, addition of iso- propanol is effective in improving the chemical yield. (c) 2007 Elsevier Ltd. All rights reserved.
A new reaction of the phenylhydrazones of 1,5-diketones. Synthesis of dihydropyran derivatives