One-pot synthesis of α-bromoesters and ketones from β-ketoesters and diketones using supported reagents system
作者:Tadashi Aoyama、Toshio Takido、Mitsuo Kodomari
DOI:10.1016/j.tetlet.2004.01.014
日期:2004.2
A simple and efficient method has been developed for the synthesis of α-bromoesters and ketonesfrom β-ketoesters and diketones in one pot using a supported reagents system, CuBr2/Al2O3–Na2CO3/Al2O3, in which β-ketoester reacts first with CuBr2/Al2O3 and the product, α-bromo-β-ketoester, reacts with Na2CO3/Al2O3 to give the final product, α-bromoesters in good yields.
已开发出一种简单有效的方法,使用支持的试剂系统CuBr 2 / Al 2 O 3 -Na 2 CO 3 / Al 2 O 3在一个锅中由β-酮酸酯和二酮合成α-溴酸酯和酮,其中β-酮酸酯首先与CuBr 2 / Al 2 O 3反应,产物α-溴-β-酮酸酯与Na 2 CO 3 / Al 2 O 3反应以高产率得到最终产物α-溴酸酯。
Simple Method for sp2–sp3 and sp3–sp3 Carbon–Carbon Bond Activation in 2-Substituted 1,3-Diketones
Simple and efficient methods were developed for sp(2)-sp(3) and sp(3)-sp(3) C-C bond-activation reactions of 2-substituted 1,3-diketones. 3-Substituted 3-bromopentane-2,4-diones were deacylated in the presence of an aromatic compound and a silica gel supported Bronsted acid containing sulfonic groups. The carbocation formed by cleavage of the sp(3)-sp(3) C-C bond of the dione alkylated the aromatic compound.
Mitani, Michiharu; Hirayama, Hiroyuki, Journal of Chemical Research, Miniprint, 1993, # 7, p. 1562 - 1572
作者:Mitani, Michiharu、Hirayama, Hiroyuki
DOI:——
日期:——
Silica Sulfuric Acid-promoted Deacylation of α-Bromo-β-diketones
Novel deacylation of α-bromo-β-diketones using silica sulfuric acid (SSA) has been developed. Deacylation of 3-bromopentane-2,4-diones and 2-bromobutane-1,3-diones were carried out in the presence of SSA in dichloroethane under mild conditions to obtain the corresponding α-bromo ketones in good to excellent yields. SSA also promoted the Friedel–Crafts type alkylation of benzene with 3-(sec-alkyl)-2,4-pentanediones to give the corresponding triarylmethanes in high yields in benzene.