Efficient and Practical Method for Synthesizing N-Heterocyclic Compounds Using Intramolecular Nucleophilic Acyl Substitution Reactions Mediated by Ti(O-i-Pr)_4/2i-PrMgX Reagent. Synthesis of Quinolones, Pyrroles, Indoles, and Optically Active N-Heter

摘要

Treatment of N-(2-or 3-alkynyl) amino esters with a low-valent titanium reagent diisopropoxy(η~2-propene)- titanium (1), generated in situ by the reaction of Ti(O-I-Pr)_4 and 2i-PrMgCl, resulted in an intramolecular nucleophilic acyl substitution (INAS) reaction to afford α-alkylidene-pyrrolidinones or -piperidinones.