1, 2, 4‐Triazol‐3‐ylidenes with an N‐2, 4‐Dinitrophenyl Substituent as Strongly π‐Accepting N‐Heterocyclic Carbenes. Issue 46 (8th October 2013)

• Record Type: Journal Article
• Authors: Sato , Tetsuo; Hirose, Yoichi; Yoshioka, Daisuke; Shimojo, Tsubasa; Oi , Shuichi
• Is Part Of: Chemistry. Volume 19:Issue 46(2013)
• Page Start: 15710
• Page End: 15718
• Publication Date: 2013-10-08
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201302567
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The synthesis and characterisation of a series of new Rh and Au complexes bearing 1, 2, 4‐triazol‐3‐ylidenes with a <italic>N</italic>‐2, 4‐dinitrophenyl (<italic>N</italic>‐DNP) substituent are described. IR, NMR, single‐crystal X‐ray diffraction and computational analyses of the Rh complexes revealed that the N‐heterocyclic carbenes (NHCs) behaved as strong π acceptors and weak σ donors. In particular, a natural bond orbital (NBO) analysis revealed that the contributions of the Rh→C_carbene π backbonding interaction energies (Δ<italic>E</italic>_bb) to the bond dissociation energies (BDE) of the RhC_carbene bond for [RhCl(NHC)(cod)] (cod=1, 5‐cyclooctadiene) reached up to 63 %. The Au complex exhibited superior catalytic activity in the intermolecular hydroalkoxylation of cyclohexene with 2‐methoxyethanol. The NBO analysis suggested that the high catalytic activity of the Au^I complex resulted from the enhanced π acidity of the Au atom.</p> </abstract>