A method for the in situ formation of N-trifluoroacetoxy succinimide (TFA-NHS) and its application in the formation of succinimidyl esters is presented. The developed method provides N-trifluoroacetyl and N-maleoyl amino acid succinimidyl esters from a variety of amino acids using a one-pot, high-yielding protocol. Investigations into the formation of an N-maleoyl amino acid succinimidyl ester supported the proposal of a revised reaction mechanism, and contributed to the optimization of the reaction conditions.
View Article and Find Full Text PDFNitrogen heterocycles can be prepared by performing ring-expansion reactions of gamma-silyloxy-gamma-lactams, which are available by the annulation reactions of allylic silanes. Nucleophilic substitution of the annulation products and subsequent translactamization of nitrogen-tethered gamma-lactams provide six-, seven-, and eight-membered ring lactams. An enantiomerically enriched delta-lactam formed from this method was elaborated to form the hydroxypiperidine core structure of the pseudodistomin alkaloids.
View Article and Find Full Text PDFA novel series of 4-[(4-cyano-2-arylbenzyloxy)-(3-methyl-3H-imidazol-4-yl)methyl]benzonitriles have been synthesized as selective farnesyltransferase inhibitors using structure-based design. X-ray cocrystal structures of compound 20-FTase-HFP and A313326-FTase-HFP confirmed our initial design. The decreased interaction between the aryl groups and Ser 48 in GGTase-I binding site could be one possible reason to explain the improved selectivity for this new series of FTase inhibitors.
View Article and Find Full Text PDFThe chemoselective allylation of acetals using allyltrimethylsilane in ionic liquids is catalyzed by TMS triflate (5.0-20.0 mol %).
View Article and Find Full Text PDFAcetals are obtained in good yields by treatment of aldehydes and ketones with trialkyl orthoformate and the corresponding alcohol in the presence of 0.1 mol % Bi(OTf)3.4H2O.
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