Fischer Carbene Complexes of Iridium(I) for Application in Catalytic Transfer Hydrogenation.

New examples of the very rare class of iridium(I) Fischer carbene complexes (FCCs) are reported from the facile transmetalation from group 6 FCCs. Postcomplexation modification of either the carbene ligand or the ancillary coligands results in a tunable Ir metal center, for unprecedented application as a (pre)catalyst in a benchmark transfer hydrogenation reaction. The introduction of an aminocarbene ligand with a pendant N-donor moiety capable of hemilabile coordination yielded the best catalytic results with turnover frequencies reaching 445 h and requiring 0.

A Hemilabile and Cooperative N-Donor-Functionalized 1,2,3-Triazol-5-Ylidene Ligand for Alkyne Hydrothiolation Reactions.

A series of novel cationic and neutral Rh complexes with an N-donor-functionalized 1,2,3-triazol-5-ylidene (TRZ) ligand (in which the pendant N donor is NHBoc, NH , or NMe ) is described. The catalytic activity of these complexes was evaluated in the hydrothiolation of alkynes. Among the catalysts, a neutral dicarbonyl complex featuring the tethered-NBoc amido-TRZ ligand proved very selective for alkyne hydrothiolation with an aryl thiol.

Electrochemical illumination of thienyl and ferrocenyl chromium(0) Fischer carbene complexes.

A series of ferrocenyl and thienyl mono- and biscarbene chromium(0) complexes 1-6 were synthesised. The complexes were characterised both spectroscopically and electrochemically, and the single crystal X-ray structure of 3 was determined. Electrochemical measurements in CH2Cl2 revealed that the carbene double bond of 1-6 is reduced to an anion radical, (-)Cr-C˙ at formal reduction potentials <-1.