An efficient access to a variety of trifluoromethyl-substituted cyclic α-amino acid derivatives based on ruthenium-catalyzed cyclotrimerization of appropriate 1,6- and 1,7-diynes with terminal and internal alkynes has been developed.
An efficient method for the preparation of functionalized α-trifluoromethyl-substituted azahistidine analogues has been developed. The method is based on the regioselective addition of allenylmagnesiumbromide to highly electrophilic imines of trifluoropyruvates and subsequent 1,3-dipolar Huisgen cycloaddition between α-propargyl-α-trifluoromethyl-α-amino esters and organic azides.
The incorporation of alpha-trifluoromethyl pyroglutamic acid into thyreotropin releasing hormone TRH, results in the complete stability of the pGlu-His bond against proteolytic degradation by pyroglutamyl aminopeptidase II. The influence of the trifluoromethyl group on structure and receptor affinity has been studied.
BURGER, KLAUS;GAA, KARL, CHEM.-ZTG., 114,(1990) N, C. 101-104