作者:Felix Lindl、Xueying Guo、Ivo Krummenacher、Florian Rauch、Anna Rempel、Valerie Paprocki、Theresa Dellermann、Tom E. Stennett、Anna Lamprecht、Tobias Brückner、Krzysztof Radacki、Guillaume Bélanger‐Chabot、Todd B. Marder、Zhenyang Lin、Holger Braunschweig
DOI:10.1002/chem.202101290
日期:2021.8.2
the cyclic conjugated diene system, which has been shown to participate in cycloadditionreactions, such as the Diels-Alder reaction with alkynes. The reaction steps leading to boranorbornadienes, borepins and tricyclic boracyclohexenes from the thermal reaction of boroles with alkynes are seemingly well understood as judged from the literature. Herein, we question the long-established mechanistic picture
we tested 7-borabicyclo[2.2.1]hepta-2,5-dienes (or 7-boranorbornadienes in short) obtained from facile [4 + 2] cycloaddition of boroles and alkynes. By formation of a Lewis adduct with an N-heterocyclic carbene (NHC), we intended to block previously reported pericyclic reactions leading to undesired ring expansion and achieve a cheletropic elimination of the borylene species instead. Our results presented