Tuning the nucleophilicity in cyclopropenylidenes.

Chemistry : a European Journal
Wolfgang W SchoellerGuy Bertrand

Abstract

Cyclopropenylidenes are Hückel aromatic pi systems in which one of the ring atoms is a carbene center. Quantum chemical calculations at the density functional level of theory, supplemented by coupled-cluster calculations, indicate that there is a sizeable energy separation between the lowest-energy singlet and triplet states of these species. Amino groups considerably increase the energy difference between these two states, whereas electron-withdrawing substituents decrease it. The 1,1-dimerization products of cyclopropenylidenes, namely, triafulvalenes, have been investigated. The calculations show that, without steric hindrance and considerable electronic stabilization, cyclopropenylidenes are kinetically unstable and dimerize. Different substituents (alkyl, silyl, terphenyl, amino, and phosphoraneiminato) were probed to tune the frontier orbital energies of cyclopropenylidenes. Accordingly, it is predicted that by a suitable choice of substituents at the olefinic positions, cyclopropenylidenes can be more nucleophilic than their five-membered ring congeners, namely, imidazol-2-ylidenes.

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Citations

Apr 17, 2010·Journal of the American Chemical Society·Hasnain A MalikJohn Montgomery
Aug 5, 2016·Inorganic Chemistry·Thibault TroadecTsuyoshi Kato
Jun 12, 2010·Journal of the American Chemical Society·Florie LavigneAntoine Baceiredo
May 8, 2014·Inorganic Chemistry·Wolfgang W Schoeller, Guido D Frey
Mar 16, 2012·Journal of the American Chemical Society·Jeffrey S Bandar, Tristan H Lambert
Dec 6, 2011·Journal of the American Chemical Society·Jekaterina PetuškovaManuel Alcarazo
Jan 10, 2013·The Journal of Organic Chemistry·Genping HuangDaesung Lee
Dec 7, 2013·Journal of the American Chemical Society·Javier CarrerasManuel Alcarazo
Jan 20, 2015·Chemistry, an Asian Journal·Daniel R TolentinoGuy Bertrand
Sep 14, 2010·Angewandte Chemie·Mohand MelaimiGuy Bertrand
Nov 29, 2013·Chemistry : a European Journal·Florie LavigneAntoine Baceiredo
Oct 1, 2009·Dalton Transactions : an International Journal of Inorganic Chemistry·Natalie FeyA Guy Orpen
Jun 23, 2011·Chemical Society Reviews·Zhi-Bin ZhuMin Shi
Nov 12, 2020·Journal of the American Chemical Society·Evan A DoudXavier Roy

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