Graduate School of Pharmaceutical Sciences, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan.
J Am Chem Soc. 2010 Apr 7;132(13):4522-3. doi: 10.1021/ja910451j.
A palladium-catalyzed dicyanative [4+2] cycloaddition reaction using dienynes with TMSCN under aerobic conditions is described. This new reaction triggered by the cyanopalladation of terminal alkynes includes regioselective direct cyanation to C-C triple bonds by TMSCN to give pi-allyl Pd intermediates, which promotes 5-exo followed by 6-endo cyclization. This protocol enables (1) the formation of four C-C bonds through one operation, (2) the construction of highly functionalized cyclohexene rings, and (3) the generation of five contiguous stereogenic centers in one operation. The intermolecular cycloaddition reaction between a conjugated enyne and methyl acrylate also proceeded in a regioselective fashion to give multifunctionalized carbocycles.
描述了在有氧条件下使用 TMSCN 的二氰基钯催化[4+2]环加成反应与二炔。该新反应由末端炔烃的氰钯化引发，包括 TMSCN 对 C-C 三键的区域选择性直接氰化，生成π-烯丙基 Pd 中间体，促进 5-endo 随后进行 6-endo 环化。该方案使（1）通过一次操作形成四个 C-C 键，（2）构建高官能化的环己烯环，以及（3）在一次操作中生成五个连续的立体中心。共轭烯炔与甲基丙烯酸甲酯的分子间环加成反应也以区域选择性的方式进行，生成多功能碳环。
