Switching of Regioselectivity in a Perfluorohexyl Iodide Mediated Synthesis of Phenylimidazo[1,2-a]pyridines

详细信息    查看全文

• 作者：Irwan Iskandar Roslan ; Gaik-Khuan Chuah and Stephan Jaenicke
• 刊名：European Journal of Organic Chemistry
• 出版年：2017
• 出版时间：January 18, 2017
• 年：2017
• 卷：2017
• 期：3
• 页码：671-675
• 全文大小：826K
• ISSN：1099-0690

文摘

3-Phenylimidazo[1,2-a]pyridines were synthesized through the perfluorohexyl iodide mediated coupling of 2-aminopyridines and phenylacetylenes. In situ iodination of the terminal alkyne by perfluorohexyl iodide reverses the polarity by generating a transient electrophilic iodoalkyne, and this alters the regioselectivity of the phenyl group. The reaction then proceeds by tandem electrophilic alkynylation and cyclization to form the fused-ring product. The protocol affords the 3-phenyl isomer with full regioselectivity and is complementary to reported methodologies for the synthesis of the 2-phenyl isomer starting from the same substrates.