Organo- and Copper-Multi-Catalyzed Pseudo Four-Component Access to <i>gem</i>
-Difluorohydrins
作者:Angela Ricucci、Jean Rodriguez、Adrien Quintard
DOI:10.1002/ejoc.201701459
日期:2018.8.1
multi‐catalytic pseudo four‐component strategy combining an aldehyde, a β‐keto‐acid and two equivalents of a fluorinating agent has been designed. Thanks to the combined effects of a secondaryamine as organocatalyst and a copper catalyst, highly volatile gem‐difluorinated intermediates can be produced and trapped in situ by a chemo‐compatible decarboxylative aldolization providing a rapid access to original
metal‐free protocol for the domino trifluoromethylthiolation/decarboxylation of β‐ketocarboxylic acids is described. The catalytic reactions take place in acetonitrile in the presence of aqueous ammonium hydroxide and N‐trifluoromethylthiosaccharin. The sequence of events and reaction mechanism were established experimentally and using density functional theory calculations. This synthetic method offers a convenient