Electronic effects on the addition of double bonds to triplet benzenes: what is the rate-determining step in biradical formation?

1989 ◽  
Vol 111 (23) ◽  
pp. 8723-8725 ◽  
Author(s):  
Peter J. Wagner ◽  
Masami Sakamoto
Keyword(s):  
Double Bonds ◽  
Electronic Effects ◽  
Rate Determining Step

Electrophilic additions to allenes. VI. The role of steric versus electronic effects in the reactions of arenesulphenyl halides with allenes

1980 ◽  
Vol 58 (24) ◽  
pp. 2737-2744 ◽  
Author(s):  
Dennis G. Garrattz ◽  
Pierre L. Beaulieu
Keyword(s):  
Positive Charge ◽  
Steric Effects ◽  
Rate Data ◽  
Electronic Effects ◽  
Rate Determining Step ◽  
Minimal Importance ◽  
Electrophilic Additions

The role of steric and electronic effects during the rate and product determining steps for the addition of arenesulphenyl chlorides to 1,3-disubstituted allenes has been briefly examined. Both effects appear to be generally of minimal importance during the rate determining step. The available rate data indicate the presence of little, if any, build up of positive charge on sulphur. These results are interpreted in terms of an SN2 attack on bivalent sulphur leading to an alkylidenethiiranium ion intermediate. Steric effects are of greater importance in the product determining step, particularly when the sulphenyl chlorides possess two bulky ortho substituents, as in the case of 2,4,6-triisopropylbenzenesulphenyl chloride.

Mechanistic studies of amination of ketenimines: change of rate-determining step by N-substituents through electronic effects

Tetrahedron ◽  
2006 ◽  
Vol 62 (1) ◽  
pp. 171-181 ◽  
Author(s):  
Kuangsen Sung ◽  
Fu-Lin Chen ◽  
Pin-Mei Huang ◽  
Shu-Min Chiang
Keyword(s):  
Mechanistic Studies ◽  
Electronic Effects ◽  
Rate Determining Step

On the rate-determining step and the ligand electronic effects in rhodium catalysed hydrogenation of enamines and the hydroaminomethylation of alkenes

2011 ◽  
Vol 1 (3) ◽  
pp. 431 ◽  
Author(s):  
José A. Fuentes ◽  
Piotr Wawrzyniak ◽  
Geoffrey J. Roff ◽  
Michael Bühl ◽  
Matthew L. Clarke
Keyword(s):  
Electronic Effects ◽  
Rate Determining Step

A DFT/MM analysis of the effect of ligand substituents on asymmetric hydrogenation catalyzed by rhodium complexes with phosphine–phosphinite ligands

2009 ◽  
Vol 87 (10) ◽  
pp. 1273-1279 ◽  
Author(s):  
Steven M. A. Donald ◽  
Anton Vidal-Ferran ◽  
Feliu Maseras
Keyword(s):  
Dft Calculations ◽  
Asymmetric Hydrogenation ◽  
Rhodium Catalyst ◽  
Experimental Results ◽  
Catalytic Process ◽  
Rhodium Complexes ◽  
Electronic Effects ◽  
Rate Determining Step ◽  
Bidentate Phosphine

DFT and DFT/MM calculations are carried out on the rate-determining step of the addition of dihydrogen to methyl-(N)-acetylaminoacrylate catalyzed by a rhodium catalyst containing a bidentate phosphine–phosphinite ligand. DFT calculations reproduce the experimental results, while DFT/MM calculations do not. The failure of DFT/MM methods for this particular problem is analyzed through a series of calculations with different partitions between the DFT and MM regions, which show that electronic effects of all ligand substituents considered are critical. The analysis of these electronic effects provides key information on the role of each of the substituents in the outcome of the overall catalytic process.

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