Catalytic enantioselective synthesis of a-aryl a-hydrazino esters and amides

Catalysts generated by combinations of Pd(TFA)and pyridine-hydrazone ligands have allowed the asymmetric 1,2-addition of aryl boronic acids toN-carbamoyl (Cbz and Fmoc) protected glyoxylate-derived hydrazones, yielding a-aryl a-hydrazino esters/amides in high enantioselectivities. Subsequent removal of the carbamoyl moiety affords key building blocks en route to hydrazinopeptides,N-aminopeptides and peptidomimetics thereof

Asymmetric Dearomatization of Phthalazines by Anion-BindingCatalysis

A straightforward methodology for the enantioselective synthesis of 1,2-dihydrophthalazines via dearomatization of phthalazines by anion-binding catalysis has been developed. The process involves the Mannich-type addition of silyl ketene acetals to in situ generated N-acylphthalazinium chlorides using a tert-leucine derived thiourea as a H-bond donor catalyst. Ensuing selective and high-yielding transformations provide appealing dihydro- and tetrahydro-phthalazines, phthalazones, and piperazic acid homologues, en route to biologically relevant molecules.Ministerio de Ciencia e Innovación de España PID2019-106358GB-C21, PID2019-106358GB-C22 - PID2022-137888NB-I00Junta de Andalucía y Fondos Europeos FEDER- P18-FR-3531, P18-FR-644 y US-126286