Studies on the coupling of substituted 2-amino-1,3-oxazoles with chloro-heterocycles
摘要:
Direct coupling of five-membered heterocyclic amines with halo-heterocycles is a notoriously recalcitrant transformation. Herein we report our findings on the coupling of substituted 2-amino-1,3-oxazoles with chloro-heterocycles. Whereas the coupling of 2-amino-1,3-oxazole is inefficient under a large variety of state-of-the-art catalytic conditions tested, coupling of an ester substituted 2-amino-1,3-oxazole is relatively efficient and provides access, via a hydrolysis-decarboxylation protocol, to the 2-amino-1,3-oxazole coupled products. (C) 2012 Elsevier Ltd. All rights reserved.
A General Catalyst for Buchwald-Hartwig Amination to Prepare Secondary Five-Membered Heteroaryl Amines with Breaking the Base Barrier
作者:Fabin Zhou、Lixue Zhang、Wenbo Hu、Bingxin Yuan、Ji-cheng Shi
DOI:10.1016/j.jcat.2023.02.018
日期:2023.3
sometimes needing strongbases, perplexes the application of the palladium-catalyzed CN cross-coupling reactions. The terphenyl phosphine TXPhos supporting palladium catalyst [(TXPhos)(allyl)PdCl] dramatically broadened the existing scope of five-membered heteroaryl substrates and made the weak bases KHCO3 and KOAc become general and optimal choices. Therefore, the barrier of bases has been broken and
底物的范围限制,特别是五元杂芳基底物通常出现在医学和生物活性分子中,以及高钯负载量和有时需要强碱,困扰着钯催化的 C N 交叉偶联反应的应用。三联苯基膦TXPhos负载钯催化剂[(TXPhos)(allyl)PdCl]大大拓宽了五元杂芳基底物的现有范围,使弱碱KHCO 3 和KOAc成为通用和优化的选择。因此,碱基屏障已被打破,并建立了通过钯催化的 C N 交叉偶联反应制备仲五元杂芳基胺的有吸引力的方案。