Efficient One-Pot Synthesis of Fluorinated Benzimidazolines, Benzothiazolines, Benzoxazolines, and Dihydrobenzoxazinones Using Gallium(III) Triflate as a Catalyst
作者:G. K. Surya Prakash、Thomas Mathew、Chiradeep Panja、Habiba Vaghoo、Karthik Venkataraman、George A. Olah
DOI:10.1021/ol062562e
日期:2007.1.1
One-pot synthesis of fluorinated benzimidazolines, benzothiazolines, benzoxazolines, and dihydrobenzoxazinones was easily achieved under mild conditions in high yields and purity through gallium(III) triflate mediated condensation-cyclization. Introduction of fluorine atoms favors the formation of the five-membered heterocycles over seven-membered heterocycles. [reaction: see text].
Nafion ® -H, a perfluoroalkanesulfonic acid resin, has been found to be a suitable solid acidcatalyst with high selectivity and catalytic activity for the one-potsynthesis of fluorinated benzimidazolines, benzothiazolines, benzoxazolines, and dihydrobenz-oxazinones. These Nafion ® -H mediated condensation-cyclization reactions were easily achieved under mild conditions in high yields and purity.