Activation of Carbon-Hydrogen Bonds via 1,2-Addition across M-X (X = OH or NH2) Bonds of d6 Transition Metals as a Potential Key Step in Hydrocarbon Functionalization: A Computational Study

Description:

Article discussing a computational study on the activation of carbon-hydrogen bonds via 1,2-addition across M-X (X = OH or NH2) bonds of d6 transition metals as a potential key step in hydrocarbon functionalization.

Creator(s):
Creation Date: October 6, 2007
Partner(s):
UNT College of Arts and Sciences
Collection(s):
UNT Scholarly Works
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Total Uses: 390
Past 30 days: 10
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Creator (Author):
Cundari, Thomas R., 1964-

University of North Texas

Creator (Author):
Grimes, Thomas V.

University of North Texas

Creator (Author):
Gunnoe, T. Brent

North Carolina State University

Publisher Info:
Publisher Name: American Chemical Society
Place of Publication: [Washington, DC]
Date(s):
  • Creation: October 6, 2007
Description:

Article discussing a computational study on the activation of carbon-hydrogen bonds via 1,2-addition across M-X (X = OH or NH2) bonds of d6 transition metals as a potential key step in hydrocarbon functionalization.

Degree:
Department: Chemistry
Note:

Reprinted with permission from the Journal of the American Chemical Society. Copyright 2007 American Chemical Society.

Note:

Abstract: Recent reports of 1,2-addition of C-H bonds across Ru-X(X = amido, hydroxo) bonds of TpRu-(PMe₃)X fragments {Tp = hydridotris(pyrazolyl)borate} suggest opportunities for the development of new catalytic cycles for hydrocarbon functionalization. In order to enhance understanding of these transformations, computational examinations of the efficacy of model d6 transition metal complexes of the form [(Tab)M-(PH3)2X]q (Tab = tris-azo-borate; X = OH, NH2; q = -1 to +2; M = Tc(I), Re(I), Ru(II), Co(III), Ir(III), Ni(IV) Pt(IV) for the activation of benzene C-H bonds, as well as the potential for their incorporation into catalytic functionalization cycles, are presented. For the benzene C-H activation reaction steps, kite-shaped transition states were located and found to have relatively little metal-hydrogen interaction. The C-H activation process is best described as a metal-mediated proton transfer in which the metal center and ligand X function as an activating electrophile and intramolecular base, respectively. While the metal plays a primary role in controlling the kinetics and thermodynamics of the reaction coordinate for C-H activation/functionalization, the ligand X also influences the energetics. On the basis of three thermodynamic criteria characterizing salient energetic aspects of the proposed catalytic cycle and the detailed computational studies reported herein, late transition metal complexes (e.g., Pt, Co, etc.) in the d6 electron configuration {especially the TabCo(PH3)2(OH)+ complex and related Co(III) systems} are predicted to be the most promising for further catalyst investigation.

Physical Description:

11 p.

Language(s):
Subject(s):
Keyword(s): activating electrophiles | benzene | C-H bonds | catalytic functionalization cycles | ligand X | transition metal complexes
Source: Journal of the American Chemical Society, 2007, Washington DC: American Chemical Society, pp. 13172-13182
Partner:
UNT College of Arts and Sciences
Collection:
UNT Scholarly Works
Identifier:
  • DOI: 10.1021/ja074125g
  • ARK: ark:/67531/metadc77141
Resource Type: Article
Format: Text
Rights:
Access: Public
Citation:
Publication Title: Journal of the American Chemical Society
Volume: 129
Page Start: 13172
Page End: 13182
Pages: 11
Peer Reviewed: Yes