The dimerization of terminal alkynes is an atom economical way of synthesizing conjugated enynes, which can be utilized as potential building blocks in organic synthesis. The challenge of alkyne dimerization is selectively producing the desired enyne isomer. Our group previously reported that a rhodium complex featuring a sterically bulky diarylamido-based PNP pincer ligand showed impressive selectivity for the trans-enyne product of terminal alkyne homodimerization. Recently, the (POCOPiPr)Rh fragment has been shown to catalyze the dimerization of terminal alkynes at room temperature; however, the catalyst produces a mixture of the trans- and gem-enyne products. A number of bulky unsymmetric PCP bisphosphinite pincer rhodium complexes have been synthesized and tested as alkyne dimerization catalysts in an attempt to obtain selectivity for the trans-enyne product. Studies examining other phosphine pincer ligands are also underway, which should provide insight into the ligand traits responsible for regioselectivity.

Synthesis and reactivity of new pincer-ligated rhodium alkyne dimerization catalysts

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.