Trifluoroacetimidoyl chloride, reaction with

Although generation and reactions of 1,1,1-trifluorobiacetyl was reported as early as in 1957, the compound was not isolated in this work [637], Trifluoromelhyl-substituted derivatives 1071 were obtained via trifluoroacetylation of hydrazones 1070 [638, 639], acylation of (trifluoroacetimidoyl)lithium derivatives 1075 [640], or condensation of trifluoroacetimidoyl chlorides 1077 with aromatic aldehydes in presence of sodium hydride [641] (Scheme 230). These methodologies were also used for the synthesis of trifluoromethyl glyoxal equivalents 1064 [640,642]. 

The gem-difluoroalkenylphosphonate (183) has been synthesised by reaction of lithiated diethyl methylphosphonate with a-trifluoromethylstyrene. 1-Substituted 5-trifluoromethyliniidazole-4-phosphonates (185) have been prepared in moderate yield by the reaction of isocyanomethylphosphonate carbanions with trifluoroacetimidoyl chlorides (184). Diphosphono-alkylation of nucleophiles has been achieved in one pot by sequential treatment of phosphonate carbanions with alkyl dichlorophosphates and the conjugate acid of the appropriate nucleophile (Scheme 23). ... 

Reaction of imidoyl chlorides with azide ion produces tetrazoles through an imidoyl azide intermediate. Thus, A -substimted trifluoroacetimidoyl chlorides undergo facile nucleophilic displacement with azide ion and subsequently cyclize to give 1 -substimted-5-trifloromethyltetrazoles (Fig. 3.99). The acetimidoyl chlorides are readily prepared by refluxing a mixmre of trifluoroacetic acid and primary amine in carbon tetrachloride in the presence of triethylamine and triphenylphosphine. 

A Rh -catalyzed tandem one-pot coupling cycUzation reaction with TMSA and trifluoroacetimidoyl chlorides delivers 2-trifluoromethylated quinolines with good regioselectivity (eq45). i... 

Zhang et al. designed a tandem C-N bond formation reaction for the assembly of 2-trifluoromethyl substituted benzimidazoles 71 from A-(2-haloaryl) trifluoroacetimidoyl chlorides 70 (Scheme 25) [57]. Cul/TMEDA-catalyzed cross coupling of 70 with primary amines following by intramolecular condensation produced 71 with 62-98% yields. 

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