Alkynyl−B(dan)s in Various Palladium‐Catalyzed Carbon−Carbon Bond‐Forming Reactions Leading to Internal Alkynes, 1,4‐Enynes, Ynones, and Multiply Substituted Alkenes
作者:Tomohiro Tani、Yuuki Sawatsugawa、Yusuke Sano、Yo Hirataka、Naomi Takahashi、Sadahiro Hashimoto、Tetsuya Sugiura、Teruhisa Tsuchimoto
DOI:10.1002/adsc.201801527
日期:2019.4.16
reactions can be achieved as more convenient one‐pot reactions, without isolating the alkynyl−B(dan) formed in situ by the zinc‐catalyzed dehydrogenative borylation of alkynes with HB(dan). In addition to direct C(sp)−B(dan) bond transformations, the C≡C bond in an alkynyl−B(dan) proved to be a promising scaffold for the construction of a multisubstituted alkene, which is synthesized by diboration of the
发现炔基-B(dan)s的C(sp)-B(dan)键可直接用于钯催化的芳基(烯基)卤化物和烯丙基碳酸酯作为亲电子试剂的碳-碳键形成反应,因此分别产生不对称的内部炔烃和未共轭的1,4-炔烃。使用酰氯作为亲电子试剂,钯催化剂在铜助催化剂的辅助下也可以促进炔酮的合成。这些反应可作为更方便的单锅反应来实现,而无需分离通过炔烃与HB(dan)进行锌催化脱氢硼化反应而原位形成的炔基-B(dan)。除了直接C(sp)-B(dan)键的转变,炔基-B(dan)中的C≡C键被证明是构建多取代烯烃的有前途的支架,该多取代烯烃通过C≡C-B(dan)的硼烷基化反应合成)部分,导致三硼烷基烯烃,随后发生区域和立体选择性的Suzuki-Miyaura交叉交叉偶联反应。举一个例子,合成具有四个不同芳基的乙烯,p- MeC 6 H 4,p- MeOC 6 H 4,p- NCC 6 H 4和p- F 3 CC 6 H 4