The direct conversion of carbamates to ureas using aluminum amides
摘要:
The conversion of carbamates into ureas using aluminum amide complexes is reported. This reaction is a convenient method to prepare bi-, tri- and tetra-substituted ureas from carbamate-protected primary or secondary amines by reaction with primary or secondary amines in the presence of stoichometric quantities of trimethylaluminum. A reactivity trend of the various carbamates was observed and methyl and benzyl carbamates were reacted selectively in the presence of t-butyl carbamates. (C) 2004 Elsevier Ltd. All rights reserved.
Cyclic esters of 3,4-dihydroxy-thiophene-1,1-dioxide compounds and
申请人:BASF Aktiengesellschaft
公开号:US04122090A1
公开(公告)日:1978-10-24
Cyclic esters of 3,4-dihydroxy-thiophene-1,1-dioxide and of the corresponding cyclopentadienone compound, and their manufacture. The compounds can be used as "solid forms" of phosgene, thiophosgene or oxalyl chloride, or as acyl transfer agents.
Rapid microscale synthesis: Solution phase parallel synthesis of a library of piperazines and piperidines using a water soluble base
作者:Yun Feng Xie、Jeffrey P. Whitten、Tina Y. Chen、Zhengyu Liu、James R. McCarthy
DOI:10.1016/s0040-4020(98)00136-7
日期:1998.4
A library of 1086 piperazines and 835 piperidines was prepared via Rapid Microscale Synthesis (RMS) using the water soluble base 1,1,3,3-tetramethylguanidine to catalyze the reactions and to simplify purification.