Synthesis of cleavamine-type indole alkaloids and their 5-nor derivatives by a ring-closing metathesis–vinyl halide Heck cyclization strategy
摘要:
An indole-templated RCM has been used to assemble the central medium-sized rings of the indole upper-half of vinorelbine and the cleavamine-type alkaloids. From these key intermediates, the bridged tetracyclic framework of the alkaloids is completed with the insertion of a 2-ethylpropeno unit, by N-alkylation followed by a challenging endocyclic vinyl halide Heck cyclization. The usefulness of the approach is illustrated with the synthesis of (+/-)-cleavamine and (+/-)-dihydrocleavamine. (C) 2013 Elsevier Ltd. All rights reserved.
Synthesis of cleavamine-type indole alkaloids and their 5-nor derivatives by a ring-closing metathesis–vinyl halide Heck cyclization strategy
摘要:
An indole-templated RCM has been used to assemble the central medium-sized rings of the indole upper-half of vinorelbine and the cleavamine-type alkaloids. From these key intermediates, the bridged tetracyclic framework of the alkaloids is completed with the insertion of a 2-ethylpropeno unit, by N-alkylation followed by a challenging endocyclic vinyl halide Heck cyclization. The usefulness of the approach is illustrated with the synthesis of (+/-)-cleavamine and (+/-)-dihydrocleavamine. (C) 2013 Elsevier Ltd. All rights reserved.
Total Synthesis of the Bridged Indole Alkaloid Apparicine
作者:M.-Lluïsa Bennasar、Ester Zulaica、Daniel Solé、Tomàs Roca、Davinia García-Díaz、Sandra Alonso
DOI:10.1021/jo901986v
日期:2009.11.6
radical cyclization constitute the central steps of two alternative approaches developed to assemble the tricyclic ABC substructure of the indolealkaloidapparicine. From this key intermediate, an intramolecular vinyl halide Heck reaction accomplished the closure of the strained 1-azabicyclo[4.2.2]decane framework of the alkaloid with concomitant incorporation of the exocyclic alkylidene substituents