A Reductive-Coupling plus Nazarov Cyclization Sequence in the Asymmetric Synthesis of Five-Membered Carbocycles
作者:Daniel J. Kerr、Jonathan M. White、Bernard L. Flynn
DOI:10.1021/jo100736p
日期:2010.11.5
Palladium-mediated hydrostannylation of alkynoyl compounds is combined with Stille-Scott cross-coupling (reductive-coupling) to give one-pot access to divinyl and aryl vinyl ketones, which undergo Nazarov cyclization to give cyclopentenones upon treatment with acid. This reaction sequence has been studied with a variety of different substitution patterns, including the use of oxazolidinone auxiliaries to achieve torquoselectivity in the Nazarov cyclization. Through a combination of good yields and moderate to good levels of stereochemical induction, this approach affords efficient, convergent, and asymmetric access to a variety of different cyclopentanoid systems.
The concise synthesis of chalcone, indanone and indenone analogues of combretastatin A4
作者:Daniel J. Kerr、Ernest Hamel、M. Katherine Jung、Bernard L. Flynn
DOI:10.1016/j.bmc.2007.02.006
日期:2007.5
A series of aryl- and aroyl-substituted chalcone analogues of the tubulin binding agent combretastatin A4 (1) were prepared, using a recently introduced one-pot palladium-mediated hydrostannylation-coupling reaction sequence. These chalcones were converted to indanones by Nazarov cyclisation, followed by oxidation to give the corresponding indenones. Indenones were also prepared using a palladium-mediated formal [3+2]-cycloaddition process between ortho-halobenzaldehydes and diarylpropynones. All compounds were assessed as inhibitors of tubulin polymerisation, but only E-31 had activity similar to that of 1. However, compound E-31 did not exhibit antiproliferative activity against the MCF-7 cell line. (c) 2007 Elsevier Ltd. All rights reserved.
Kerr, Daniel J.; Metje, Christiane; Flynn, Bernard L., Chemical Communications, 2003, # 12, p. 1380 - 1381
作者:Kerr, Daniel J.、Metje, Christiane、Flynn, Bernard L.