علیرضا حسنی نژاد

Organocatalyst trityl chloride (Ph CCl), by in situ formation of trityl carbocation with inherent instability, ef?ciently promotes the cross-aldol condensation reaction between cycloalkanones and arylaldehydes in solvent-free and homogeneous media to afford a,a transformations based on new reactivity concepts have been identi?ed, often with no counterpart in the more established catalysis regimens [1–9]. Triarylmethyl chlorides (Ar CCl) are an attractive class of small-molecule organocatalysts, which have been utilized to promote a few 3 organic transformations by in situ formation of triarylmethyl carbocations [6–9]. It is noteworthy that the inherent instability of carbocations has precluded up to now their use in catalysis with decent turnover numbers [7]. The aldol condensation reaction has been widely applied for carbon–carbon bond formation in organic synthesis [10–12]. Among them, the cross-aldol condensation of cycloalkanones with arylaldehydes leading to a,a 0 3 bis(arylidene)cycloalkanones in high yields. Moreover, an attractive and plausible mechanism based on observations and the literature is proposed for the reaction.