A Computational Study of the Hofmann Elimination Pathway for the MoritaBaylis-Hillman Reaction Under DABCO Catalysis. Participation of a Bridge-Head Ylide
Keyword(s):
In comparison to the popular pathway involving proton-transfer via a four-centred cyclic transition state structure, the recently proposed overall lower energy pathway involving proton-transfer via a seven-centred cyclic transition state structure followed by Hofmann elimination for the Me<sub>3</sub>N-catalyzed Morita-Baylis-Hillman reaction is applicable to the DABCO-catalyzed reaction equally well. This finding clearly establishes that the zwitterion at the bridge-head in DABCO is well tolerated. Also, the activation free energy of the rate-limiting aldol reaction under DABCO-catalysis is lower than that under Me<sub>3</sub>N-catalysis, suggesting that DABCO is likely a better catalyst to achieve faster conversion.
2020 ◽
2014 ◽
Vol 79
(15)
◽
pp. 7025-7031
◽
1975 ◽
Vol 97
(12)
◽
pp. 3447-3452
◽
1985 ◽
Vol 107
(2)
◽
pp. 307-312
◽
Keyword(s):
1984 ◽
Vol 106
(4)
◽
pp. 1113-1117
◽
Keyword(s):
Keyword(s):