Metal-free binding and coupling of carbon monoxide at a boron–boron triple bond
作者:Holger Braunschweig、Theresa Dellermann、Rian D. Dewhurst、William C. Ewing、Kai Hammond、J. Oscar C. Jimenez-Halla、Thomas Kramer、Ivo Krummenacher、Jan Mies、Ashwini K. Phukan、Alfredo Vargas
DOI:10.1038/nchem.1778
日期:2013.12
Many metal-containing compounds, and some metal-free compounds, will bind carbon monoxide. However, only a handful of metal-containing compounds have been shown to induce the coupling of two or more CO molecules, potentially a method for the use of CO as a one-carbon-atom building block for the synthesis of organic molecules. In this work, CO was added to a boronâboron triple bond at room temperature and atmospheric pressure, resulting in a compound into which four equivalents of CO are incorporated: a flat, bicyclic, bis(boralactone). By the controlled addition of one CO to the diboryne compound, an intermediate in the CO coupling reaction was isolated and structurally characterized. Electrochemical measurements confirm the strongly reducing nature of the diboryne compound. The coupling of carbon monoxide molecules is an attractive prospect for organic synthesis, but only a few metal complexes are known to do this. A compound containing a boronâboron triple bond has now been shown to induce the coupling of four CO molecules, through an intermediate with a single CO.