Please use this identifier to cite or link to this item:
|Title:||Substituent effects on ring opening of 2-furylcarbenes: An ab initio study|
|Source:||Sun, Y., Wong, M.W. (1999-12-10). Substituent effects on ring opening of 2-furylcarbenes: An ab initio study. Journal of Organic Chemistry 64 (25) : 9170-9174. ScholarBank@NUS Repository. https://doi.org/10.1021/jo991131p|
|Abstract:||The ring-opening reactions of a series of substituted 2-furylcarbenes were investigated by G2(MP2,SVP) theory. The substitutents examined include CH3, SiH3, NH2, OH, F, Cl, Br, and CH=CH2. The furan ring-opening reaction is predicted to proceed via a six-membered ring transition state, which was described by Herges as a coarctate transition state. The calculated activation barrier depends strongly on the nature of the substituent group, ranging from 8 to 83 kJ mol-1. Substituent effects on the carbene reactant and ring-opening transition state were analyzed using isodesmic reactions. Methyl and vinyl substituents stabilize the reactant and transition state to a similar extent. On the other hand, NH2, OH, F, Cl, and Br substituents raise the energy barrier due to the greater stabilizing effect on the reactant than the transition state. The predicted aptitude of ring opening in 2-furylcarbenes is in the order SiH3 > H > CH=CH2 > CH3 > Br > Cl > F > NH2 > OH. This calculated trend is consistent with experimental observations. The amino-, hydroxyl-, and fluoro-substituted 2-furylcarbenes are predicted to be experimentally accessible species in the gas phase. The effects of substitution on furan oxygen of 2-furylcarbene are also reported.|
|Source Title:||Journal of Organic Chemistry|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Feb 22, 2018
WEB OF SCIENCETM
checked on Jan 22, 2018
checked on Feb 19, 2018
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.