Chloro({2-[mesityl(quinolin-8-yl-κN)boryl]-3,5-dimethyl-phenyl}methyl-κC)palladium(II) as a Catalyst for Heck Reactions

Molecules

Sem Raj Tamang²  James D. Hoefelmeyer¹ 

[1] Department of Chemistry, University of South Dakota, 414 E. Clark St., Vermillion, SD 57069, USA; E-Mail

关键词: Heck reaction;    catalysis;    organometallic;    palladium;    frustrated Lewis pair;    non-classical ligand;   

DOI  :  10.3390/molecules200712979

来源: mdpi

【 摘 要 】

We recently reported an air and moisture stable 16-electron borapalladacycle formed upon combination of 8-quinolyldimesitylborane with bis(benzonitrile)dichloropalladium(II). The complex features a tucked mesityl group formed upon metalation of an ortho-methyl group on a mesityl; however it is unusually stable due to contribution of the boron p_z orbital in delocalizing the carbanion that gives rise to an η⁴-boratabutadiene fragment coordinated to Pd(II), as evidenced from crystallographic data. This complex was observed to be a highly active catalyst for the Heck reaction. Data of the catalyst activity are presented alongside data found in the literature, and initial comparison reveals that the borapalladacycle is quite active. The observed catalysis suggests the borapalladacycle readily undergoes reductive elimination; however the Pd(0) complex has not yet been isolated. Nevertheless, the ambiphilic ligand 8-quinolyldimesitylborane may be able to support palladium in different redox states.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.