介绍了bafilomycin A 1的收敛合成,bafilomycin A 1是V型ATP酶的有效抑制剂。合成依赖于三氟甲磺酸锌介导的复杂烯炔向非对映体的非对映选择性加成,作为关键片段偶联的敏感醛。钌催化的炔丙基炔的反还原可有效地安装所需的C10–C13反式,反式二烯亚单元,从而实现了传统钯催化交叉偶联策略的替代策略。三元醇中仲羟基的高度选择性氧化为合成完成奠定了基础。
1,4-Pentenyne as a Five-Carbon Synthon for Efficient and Selective Syntheses of Natural Products Containing 2,4-Dimethyl-1-penten-1,5-ylidene and Related Moieties by Means of Zr-Catalyzed Carboalumination of Alkynes and Alkenes
作者:Gangguo Zhu、Ei-ichi Negishi
DOI:10.1002/chem.200701512
日期:2008.1
Two highly efficient protocols for enantioselective synthesis of 2,4-dimethyl-1-penten-1,5-ylidene derivatives involve the combined use of the Zr-catalyzed methylalumination of alkynes (ZMA) and the Zr-catalyzed asymmetric carboalumination of alkenes (ZACA). The ZMA/ZACA protocol has been applied to the synthesis of a nafuredin intermediate 14 and a potential intermediate 18 for milbemycin beta 3,
A convergent synthesis of bafilomycinA1 (see structure) is presented, and relies on the Zn(OTf)2‐mediated diastereoselective addition of alkynes to aldehydes. The coupling of a complex enyne with a sensitive aldehyde in the key step, in combination with a novel strategy for a chemoselective trans‐reduction of the enyne, establishes an alternative to standard palladium‐catalyzed cross‐coupling strategies
提出了聚合反应的bafilomycin A 1(见结构),并依赖于炔烃向醛类的Zn(OTf)2介导的非对映选择性加成。在关键步骤中,将复杂的烯炔与敏感的醛偶联,再结合用于烯炔的化学选择性反式还原的新策略,为形成1,3的标准钯催化交叉偶联策略提供了另一种选择-二烯。
Synthesis of the C6C16 polyene fragment of ratjadone, a potent cytotoxic metabolite from Sorangium cellulosum
作者:Eckhard Claus、Markus Kalesse
DOI:10.1016/s0040-4039(99)00716-9
日期:1999.5
The Pd-catalyzed synthesis of the polyene fragment of ratjadone is described. This strategy employs the Stille-coupling for the coupling of the tetrahydropyran subunit and the Suzuki coupling for attaching the unsaturated lactone to the polyene chain. (C) 1999 Elsevier Science Ltd. All rights reserved.