Palladium-Catalyzed Chemoselective Intramolecular Cyclization of 2-Bromoaryl Alkenenitriles
作者:Jui-Hui Deng、Huo-Mu Tai、Chau-Chen Yang
DOI:10.1002/jccs.200000043
日期:2000.4
The chemoselectivity in the palladium-catalyzed intramolecular cyclization of 2-(o-bromoaryl)-alkenenitriles depends on the nature of α-substitutents. 2-(o-Bromoanilino)alkenenitriles attacked the cyano group, followed by the cyano group transposition and hydrolysis, to give o-(methylamino)benzonitrile. 2-(o-Bromobenzyl)alkenenitriles, 2-(o-bromophenylthio)alkenenitriles and 2-(o-bromophenoxy)-alkenenitriles
钯催化的 2-(邻溴芳基)-烯腈分子内环化的化学选择性取决于 α-取代基的性质。2-(邻溴苯胺基)烯腈攻击氰基,随后氰基转位和水解,得到邻-(甲氨基)苄腈。2-(邻溴苄基)烯腈、2-(邻溴苯硫基)烯腈和 2-(邻溴苯氧基)-烯腈攻击烯属双键并导致 L-乙烯基-2-吲哚腈、1,2,3,4 -四氢萘-2-甲腈、3,4-二氢-2H-苯并[b]硫胺-2-甲腈和3,4-二氢-2H-苯并[b]恶英-2-甲腈。提出了钯催化芳基化的一般机制。