Structure–activity relationship of dihydroimidazo-, dihydropyrimido, tetrahydrodiazepino-[2,1-b]-thiazoles, and -benzothiazoles as an acylation catalyst
作者:Sentaro Okamoto、Yuzo Sakai、Saki Watanabe、Shohei Nishi、Aya Yoneyama、Hitomi Katsumata、Yu Kosaki、Rumi Sato、Megumi Shiratori、Misuzu Shibuno、Tsukasa Shishido
DOI:10.1016/j.tetlet.2014.01.135
日期:2014.3
synthesized by a condensation reaction of cyclic thioureas 15 and α-bromoacetophenones 14. Investigations of the acylation reactions of 1-phenylethanol with acid anhydrides in the presence of these cyclic isothiourea catalysts revealed their structure–activity relationships. Remarkable electronic effects resulting from substituent(s) on a benzo or phenyl moiety and the influence of the size of the annulating
环状异硫脲1,2,3,和4通过一个四步骤程序由相应的合成邻-bromoanilines 10经由Pd或铜催化的环化-苯并噻唑形成。Nonbenzo类似物7,8,和9通过循环硫脲的缩合反应合成的15和α-bromoacetophenones 14。在这些环状异硫脲催化剂的存在下,对1-苯乙醇与酸酐的酰化反应的研究表明了它们的结构活性关系。观察到由苯并或苯基部分上的一个或多个取代基引起的显着电子效应以及环环尺寸的影响。供电子取代基的引入提高了反应速率。还研究了对3型和7型手性催化剂的一些取代作用。