71441-79-7Relevant articles and documents
CHLORIERENDE METHYLIERUNG VON ALDEHYD- UND KETOGRUPPEN MIT NIOB-REAGENZIEN SOWIE AUFKLAERUNG DES MECHANISMUS
Kauffmann, Thomas,Abel, Thomas,Neiteler, Gabriele,Schreer, Martin
, p. 503 - 506 (2007/10/02)
The reagents MeNbCl4 and Me2NbCl3, applied as isolated pure compounds, react with ketones in preparatively useful yields according to RR'CO -> RR'C(Cl)CH3.Whereas benzaldehyde reacts with MeNbCl4 analogously, the aliphatic aldehyde heptanal forms beside the expected product two cinechlorination products, indicating a mechanism via radicals.MeNbCl4 is highly aldehyde-vs.-ketone selective.Conversely, high ketone-vs.-aldehyde selectivity is achievable by application of MeNbCl4*PPh3 or NbCl5*PPh3 + 1.5 Me2Zn.