ChemInform Abstract: TRANSITION-STATE PLIABILITY IN NITROGEN-TO-NITROGEN PROTON TRANSFER

An new overall lower energy pathway for the amine-catalysed Morita-Baylis-Hillman reaction is proposed from computations at the M06-2X/6-311++G(d,p) level. The pathway involves proton-transfer from the ammonium ion to the alkoxide formed from the aldol reaction through a seven-membered ring transition state (TS) structure followed by highly exothermic Hofmann<i> </i>elimination through a five-membered ring TS structure to form the product and also release the catalyst to carry on with the process all over again.

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An Alternate Energy-Conserved Pathway for the Morita-Baylis-Hillman (MBH) Reaction

10.26434/chemrxiv.12011673 ◽

2020 ◽

Author(s):

Veejendra Yadav

Keyword(s):

Proton Transfer ◽

Transition State ◽

Lower Energy ◽

Aldol Reaction ◽

Membered Ring ◽

Ammonium Ion ◽

Alternate Energy ◽

Ring Transition State ◽

Mbh Reaction

An new overall lower energy pathway for the amine-catalysed Morita-Baylis-Hillman reaction is proposed from computations at the M06-2X/6-311++G(d,p) level. The pathway involves proton-transfer from the ammonium ion to the alkoxide formed from the aldol reaction through a seven-membered ring transition state (TS) structure followed by highly exothermic Hofmann<i> </i>elimination through a five-membered ring TS structure to form the product and also release the catalyst to carry on with the process all over again.

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The effect of benzoannulation on the transition state and the proton transfer equilibrium in di(2-pyridyl)methane derivatives

New Journal of Chemistry ◽

10.1039/c1nj20108e ◽

2011 ◽

Vol 35 (7) ◽

pp. 1433 ◽

Cited By ~ 7

Author(s):

Borys Ośmiałowski ◽

Tadeusz M. Krygowski ◽

Justyna Dominikowska ◽

Marcin Palusiak

Keyword(s):

Proton Transfer ◽

Transition State

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Variational transition state theory calculation of proton transfer dynamics in (H3CH...CH3)-

The Journal of Physical Chemistry ◽

10.1021/j100111a010 ◽

1993 ◽

Vol 97 (9) ◽

pp. 1765-1769 ◽

Cited By ~ 17

Author(s):

Alan D. Isaacson ◽

Lan Wang ◽

Steve Scheiner

Keyword(s):

Proton Transfer ◽

Transition State ◽

Transition State Theory ◽

State Theory ◽

Variational Transition State Theory ◽

Theory Calculation ◽

Variational Transition State

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Model calculations of isotope effects. VII. Deprotonation of 2-nitropropane by oxy anion bases

Australian Journal of Chemistry ◽

10.1071/ch9831503 ◽

1983 ◽

Vol 36 (8) ◽

pp. 1503

Author(s):

DJ McLennan

Keyword(s):

Proton Transfer ◽

Transition State ◽

Isotope Effects ◽

Experimental Results ◽

Electron Delocalization ◽

Model Calculations ◽

Charge Delocalization ◽

Successful Model ◽

Deuterium Isotope Effects ◽

State Models

Model calculations of primary and secondary deuterium isotope effects for the hydroxide-induced deprotonation of 2-nitropropane are reported. Various transition-state models have been examined in an effort to reproduce experimental results. A purely pyramidal transition state in which proton transfer has run far ahead of carbon rehybridization and charge delocalization is a successful model as far as isotope effects are concerned, but may fail on other counts. Three incipient trigonal models for the transition state have been tested, and, although none can be firmly eliminated by the resultant isotope effects, those involving the proton transfer's running ahead of electron delocalization and perhaps carbon rehybridization are favoured.

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