钯催化硼基化邻-碳硼烷偶联反应制备3,6-双芳基-邻-碳硼烷（英文）

Palladium-Catalyzed Cross-Coupling Reactions of Borylated o-Carborane: Synthesis of 3,6-Diaryl-o-carboranes

钯催化碳硼烷基-3,6-二硼酸频哪醇酯与芳基溴化物反应,以中等的收率得到一系列硼顶点取代的3,6-双芳基-邻-碳硼烷.反应中使用(1,5-环辛二烯)二氯化钯/三环己基膦作为催化体系,可以避免钯催化芳基-芳基交换及直接硼氢键芳基化的副产物生成.反应路径包括氧化加成、离子交换、转金属以及还原消除过程.

Palladium catalyzed cross-coupling of 3,6-(Bpin)2-o-carborane (Bpin--pinacolatoboryl)with aryl bromides has been achieved,leading to the formation of a series of B(3,6)-diarylated-o-carborane derivatives in moderate yields.In this reaction,PdCl2(cod)/tricyclohexylphosphine was used as catalyst to avoid the formation of palladium-catalyzed aryl-aryl exchange and direct B-H arylation by-products.A possible mechanism is proposed,involving a tandem sequence of oxidative' addition,anion exchange,transmetalation,and reductive elimination.