Bis(diisopropylamino)carbene deoxygenates the carbonyl group of aroylimines Ar–C(O)–N=C(CF3)2 to form alkenes, which formally result from the coupling of two carbenes, [Ar–C(:)–N=C(CF3)2] and [(iPr2N)2C:]. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

The P═C ylidic bond of phosphorus ylides is able to dissociate with the formation of the appropriate phosphanes and carbenes. For example, ylide 3 obtained from diphosphane 1 and acyl imines 2 is c...

The phosphorus ylides RPh(2)p=C(Mes)N=C(CF3)(2) [R = Ph, Ph2P(O)CH2] in solution undergo reversible dissociation of the P=C ylidic bond to give phosphanes RPh2P and the carbene MesC(:)N=C(CF3)(2). The latter can be trapped as its mesomeric nitrile ylide by treatment with cyclohexene or phenyl isocyanate to give cyclic addition products. (c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007.

Carbene-nitrile ylide 2 undergoes an unusual non-symmetrical dimerization catalyzed by stable bis(diisopropylamino)carbene. (c) 2007 Elsevier Ltd. All rights reserved.