The first totalsynthesis of (+)-gregatin E and a new totalsynthesis of (+)-gregatin B are described. Key features of our synthetic approach involve a palladium-catalyzed cyclization–methoxycarbonylation of optically active propargylic acetate and a Suzuki–Miyaura coupling or CuTC-mediated coupling reaction. The absolute configuration of (+)-gregatin E (5R,5′S) is proposed.
Asymmetric Hydrovinylation of Vinylindoles. A Facile Route to Cyclopenta[<i>g</i>]indole Natural Products (+)-<i>cis</i>-Trikentrin A and (+)-<i>cis</i>-Trikentrin B
作者:Wang Liu、Hwan Jung Lim、T. V. RajanBabu
DOI:10.1021/ja3004733
日期:2012.3.28
Vinylindoles undergo Ni(II)-catalyzed asymmetric hydrovinylation under very mild conditions (-78 °C, 1 atm ethylene, 4 mol % catalyst) to give the corresponding 2-but-3-enyl derivatives in excellent yields and enantioselectivities. Hydroboration of the alkene and oxidation to an acid, followed by Friedel-Craftsannulation, gives an indole-annulated cyclopentanone that is a suitable precursor for the
Synthèse et thermolyse éclair d'esters α-tributylstanniques
作者:J. Georges Duboudin、Max Ratier、Bruno Trouve
DOI:10.1016/0022-328x(87)80020-7
日期:1987.9
Total synthesis of (±)-cis-trikentrin B via intermolecular 6,7-indole aryne cycloaddition and Stille cross-coupling
作者:Nalin Chandrasoma、Neil Brown、Allen Brassfield、Alok Nerurkar、Susana Suarez、Keith R. Buszek
DOI:10.1016/j.tetlet.2012.11.125
日期:2013.2
An efficient total synthesis of the annulated indole natural product(+/-)-cis-trikentrin B was accomplished by means of a regioselectively generated 6,7-indole aryne cycloaddition via selective metal-halogen exchange from a 5,6,7-tribromoindole. The unaffected C-5 bromine was subsequently used for a Stille cross-coupling to install the butenyl side chain and complete the synthesis. This strategy provides rapid access into the trikentrins and the related herbindoles, and represents another application of this methodology to natural products total synthesis. The required 5,6,7-indole aryne precursor was prepared using the Leimgruber-Batcho indole synthesis. (C) 2012 Elsevier Ltd. All rights reserved.
An efficient synthesis of 2-aryl and 2-alkenyl-3-alkoxy-cyclohexenones by a modified Stille reaction
作者:M.Scott Furness、T.Philip Robinson、David J. Goldsmith、J.Phillip Bowen
DOI:10.1016/s0040-4039(98)02424-1
日期:1999.1
A general, direct procedure for the synthesis of 2-aryl and 2-alkenyl-3-alkoxy-cyclohexenones using a modified Stille coupling is described. (C) 1998 Elsevier Science Ltd. All rights reserved.