Studies Of Gold-catalyzed Cascade Cyclization Reaction Of Alkyne Involved And Synthesis Of Nitrogen Heterocyclic Compounds

Nitrogen-containing heterocyclic compounds have been one of the most active fields in organic chemistry because of its good biological activity and material properties.The development of efficient,fast,and convenient accesses to synthesize these compounds has aroused considerable interests in recent years.Indolizine and indolinone derivatives are widely exist in natural products and bioactive molecules.Multiple-component cascade reaction can afford complicated molecular structures from simple starting materials.Herein,we developed a simple and easy route to the indolizine and 3-indolinone by gold-catalyzed cascade cyclization of alkynes.1.The cascade cyclization reaction of nucleophilies with 1-?1-alkynyl?-cyclopropyl pyridines was studied to synthesze indole oxazine derivatives.The optimal reaction conditions selected by the examination of different transition metals,solvents,and temperature.With 5 mol% of IPrAuCl/AgNTf₂,the reaction proceeds efficiently in DCE at 70 ? to give the desired products in 43% to 95% yield and when tert-butylsulfinamide was used as nucleophile,indolizine substituted ketone could be got.2.Asymmetric cascade cyclization reaction of indole with 1-nitro-2-?phenylethynyl?benzene was studied.The optimal reaction conditions were found after the screening of chiral phosphoric acids,transition metals,solvents as well as the temperature.With 10 mol% chiral phosphoric acid l,7 mol% AuCl₃ as catalyst and 3? molecular sieve as additive,the reaction proceeds efficiently in toluene at-20 or 0 ? to give the desired products in 62% to 96% yield and up to 95% enantioselectivity.