Alkynylboronates and -boramides in CoI- and RhI-Catalyzed [2+2+2] Cycloadditions: Construction of Oligoaryls through Selective Suzuki Couplings
作者:Laura Iannazzo、K. Peter C. Vollhardt、Max Malacria、Corinne Aubert、Vincent Gandon
DOI:10.1002/ejoc.201100371
日期:2011.6
borylated alkynes, followed by Suzuki cross-couplings with aryl halides. Ethynylboryl pinacolate took part in cobalt-catalyzed [2+2+2] cycloadditions of all types investigated (i.e., all-intermolecular cyclotrimerization, diyne-yne cocyclization, and all-intramolecular triyne cycloisomerization). The resulting platforms gave rise to linear and angular ter- and quateraryls after Pd-catalyzed cross-coupling
低聚芳基是通过过渡金属催化的硼化炔烃的 [2+2+2] 环加成反应制备的,然后是 Suzuki 与芳基卤化物的交叉偶联。Ethynylboryl pinacolate 参与研究的所有类型的钴催化 [2+2+2] 环加成反应(即,全分子间环三聚、二炔-炔共环化和全分子内三炔环异构化)。在 Pd 催化的交叉偶联后,所得平台产生线性和有角的三和四芳基。此外,还开发了第一个涉及炔基萘硼酰胺的 [2+2+2] 环加成反应。这些衍生物可以在作为催化剂的铑配合物存在下与二炔共环化。因为硼酰胺基团在 Suzuki 偶联条件下是无活性的,但可以很容易地脱保护以提供活性基团,