Shen Yunjun, Zhang Kang, Liang Xuewei, Dontha Rakesh, Duttwyler Simon
Department of Chemistry , Zhejiang University , 310027 Hangzhou , Zhejiang , P. R. China . Email:
Chem Sci. 2019 Mar 4;10(15):4177-4184. doi: 10.1039/c9sc00078j. eCollection 2019 Apr 21.
Palladium-catalyzed dehydrogenative B-H/C-H cross coupling of monocarborane anions with alkenes is reported, allowing for the first time the isolation of selectively penta-alkenylated boron clusters. The reaction cascade is regioselective for the cage positions, leading directly to B2-6 functionalization. Under mild and convenient conditions, styrenes, benzylic alkenes and aliphatic alkenes are demonstrated to be viable coupling partners with exclusive vinyl-type B-C bond formation. Multiple subsequent transformations provide access to directing group-free products, chiral derivatives and penta-alkylated cages. The five-fold coupling, combined with the latter reactions, represents a powerful methodology for the straightforward synthesis of new classes of boron clusters.
报道了钯催化单碳硼烷阴离子与烯烃的脱氢B-H/C-H交叉偶联反应，首次实现了选择性五烯基化硼簇的分离。该反应级联对笼状位置具有区域选择性，直接导致B2-6官能化。在温和便捷的条件下，苯乙烯、苄基烯烃和脂肪族烯烃被证明是可行的偶联伙伴，可专一性地形成乙烯基型B-C键。多个后续转化反应可得到无导向基团的产物、手性衍生物和五烷基化笼状结构。这种五重偶联反应与后续反应相结合，为直接合成新型硼簇提供了一种强大的方法。
