
TY  - JOUR
A1  - Heard, GL 
A1  - Yates, BF 
T1  - Steric and Electronic Effects on the Mechanism of the Stevens Rearrangement&#8212;Large Organic Ylides of Unusually High Symmetry
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1994
VL  - 47
IS  - 9
SP  - 1685
EP  - 1694
KW  - 
UR  - https://doi.org/10.1071/CH9941685 
N2  - Ab initio molecular orbital theory has been used to study the Stevens rearrangement of trimethylammonium methylide, dimethylammonium formylmethylide and trimethylammonium formylmethylide . For each system, the rearrangement is predicted to proceed via dissociation to two radical species followed by recombination to the appropriate alkylamine . In no case is the concerted pathway competitive. Steric effects are less important than electronic effects in stabilizing the ylides, and the introduction of a carbonyl group lowers the energy barrier towards the ylides is predicted to have rigorous C8 symmetry; this unusual situation is brought about by the nature of the substituents around the positive nitrogen and the planarity of the remaining negative portion of the molecule. 
ER  -

