Loading…

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, NH2, or NMe2) is described. The catalytic activity of these complexes was evaluated in the hydrothiolation of alkynes. Among the catalysts,...

Full description

Saved in:
Bibliographic Details
Published in:Chemistry : a European journal 2017-01, Vol.23 (6), p.1393-1401
Main Authors: Strydom, Ian, Guisado‐Barrios, Gregorio, Fernández, Israel, Liles, David C., Peris, Eduardo, Bezuidenhout, Daniela I.
Format: Article
Language:English
Subjects:
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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, NH2, or NMe2) 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. Remarkably, the reaction could be carried out in the absence of pyridine or base additive. In addition, during the reaction, no evidence for oxidative addition of the thiol S−H bond was observed, strongly suggesting a reaction pathway in which a bifunctional ligand is involved. Experimental and theoretical mechanistic investigations suggest a ligand‐assisted deprotonation of thiol, hemilabile dissociation of amine from the metal, and thiolate coordination, which is indicative of a different reaction mechanism to those previously reported for related alkyne hydrothiolation reactions. Cooperation in action! A ligand‐ assisted acid‐base thiol‐activation strategy is reported for the regioselective hydrothiolation of alkynes mediated by a rhodium(I) catalyst.
ISSN:0947-6539
1521-3765
DOI:10.1002/chem.201604567