The dearomative[5+1]annulation of 2-methylindoles with new five-membered synthons O-alkyl orthooxybenzaldehydes was developed unprecedentedly through cascade[1,5]-hydride transfer/dearomativecyclization in HFIP for th...The dearomative[5+1]annulation of 2-methylindoles with new five-membered synthons O-alkyl orthooxybenzaldehydes was developed unprecedentedly through cascade[1,5]-hydride transfer/dearomativecyclization in HFIP for the synthesis of spirochromanes bearing the 2-methylindolenine skeleton.Inaddition,the dual alkylation of the methyl group of 2-methylindolenines was achieved by sequential operation through the redox neutral[5+1]annulation with the second five-membered synthon N-alkylortho-aminobenzaldehyde,providing the chromane and tetrahydroquinoline fused spiroindolenines ingood yields.Furthermore,the auxiliary group that facilitates the hydride transfer process could be simplyremoved.展开更多
基金supported by the National Natural Science Foundation of China(21978144,21672208 and 21372218)the Support Plan on Science and Technology for Youth Innovation of Universities in Shandong Province(2019KJM002)+1 种基金the financial support from the Talents of High Level Scientific Research Foundation(6651118009 and 6631121010)the start-up fund for the Recruited Talent of Xihua University(Z201098).
文摘The dearomative[5+1]annulation of 2-methylindoles with new five-membered synthons O-alkyl orthooxybenzaldehydes was developed unprecedentedly through cascade[1,5]-hydride transfer/dearomativecyclization in HFIP for the synthesis of spirochromanes bearing the 2-methylindolenine skeleton.Inaddition,the dual alkylation of the methyl group of 2-methylindolenines was achieved by sequential operation through the redox neutral[5+1]annulation with the second five-membered synthon N-alkylortho-aminobenzaldehyde,providing the chromane and tetrahydroquinoline fused spiroindolenines ingood yields.Furthermore,the auxiliary group that facilitates the hydride transfer process could be simplyremoved.