Regiodivergent Palladium-Catalyzed Alkene Difunctionalization Reactions for the Construction of Methylene Cyclobutanes and Methylene Cyclopentanes
作者:Evan C. Bornowski、James H. Shepich、Paige M. Carpenter、Derick R. White、Jessica E. Hatt、John P. Wolfe
DOI:10.1021/acs.orglett.2c03308
日期:2022.11.11
palladium-catalyzed alkene difunctionalization reactions between diethyl malonate and 1,5-dienes bearing a triflate group at C2 are described. Use of tris(2,4-di-tert-butylphenyl)phosphite as a ligand leads to 4-exo-cyclization/functionalization to afford malonate-substituted methylene cyclobutanes. In contrast, the 1,2-bis(diphenylphosphino)benzene ligand provides methylene cyclopentanes via 5-endo-cyclization/functionalization
描述了丙二酸二乙酯和在 C2 处带有三氟甲磺酸酯基团的 1,5-二烯之间的区域发散钯催化的烯烃双官能化反应。使用亚磷酸三(2,4-二叔丁基苯基)酯作为配体导致4-外环化/官能化,得到丙二酸酯取代的亚甲基环丁烷。相反,1,2-双(二苯基膦)苯配体通过5-内环化/官能化提供亚甲基环戊烷。五元环形成反应通过烯醇化亲核试剂的反碳钯化发生,而四元环形成反应通过束缚烯烃的顺-4-外-迁移插入进行,然后是C(sp 3 )–C (sp 3 ) 从 (烷基)Pd(II)(丙二酸)络合物中形成键还原消除。