title: Gold-Catalyzed Formal [4+1]/[4+3] Cycloadditions of Diazo Esters with Triazines.
abstract: Reported herein is the unprecedented gold-catalyzed formal [4+1]/[4+3] cycloadditions of diazo esters with hexahydro-1,3,4-triazines, thus providing five- and seven-membered heterocycles in moderate to high yields under mild reaction conditions. These reactions feature the use of a gold complex to accomplish the diverse annulations and the first example of the involvement of a gold metallo-enolcarbene in a cycloaddition. It is also the first utilization of stable triazines as formal dipolar adducts in the carbene-involved cycloadditions. Mechanistic investigations reveal that the triazines reacted directly, rather than as formaldimine precursors, in the reaction process.
authors.affiliation: Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Pharmaceutical Engineering & Life Science, Changzhou University, 1 Gehu Road, 213164, Changzhou, China.
authors.forename: Chenghao
authors.initials: C
authors.lastname: Zhu
authors.affiliation: Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Pharmaceutical Engineering & Life Science, Changzhou University, 1 Gehu Road, 213164, Changzhou, China.
authors.forename: Guangyang
authors.initials: G
authors.lastname: Xu
authors.affiliation: Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Pharmaceutical Engineering & Life Science, Changzhou University, 1 Gehu Road, 213164, Changzhou, China. jtsun@cczu.edu.cn, jtsun08@gmail.com.
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Sun
keywords: cycloaddition; diazo compounds; gold; heterocycles; reaction mechanisms