Synthesis of Amphidinolide T1 via Catalytic, Stereoselective Macrocyclization
摘要:
Two nickel-catalyzed reductive coupling reactions of alkynes were instrumental in a modular, stereoselective synthesis of amphidinolide T1 (1). The C13-C21 fragment was prepared from two simple starting materials that were joined in a catalytic alkyne-epoxide fragment coupling operation, whereas an intramolecular aldehyde-alkyne reductive coupling simultaneously formed the final carbon-carbon bond of the macrocycle and established the C13 carbinol configuration with complete selectivity in the desired fashion.
Synthesis of Amphidinolide T1 via Catalytic, Stereoselective Macrocyclization
作者:Elizabeth A. Colby、Karen C. O'Brie、Timothy F. Jamison
DOI:10.1021/ja039716v
日期:2004.2.1
Two nickel-catalyzed reductive coupling reactions of alkynes were instrumental in a modular, stereoselective synthesis of amphidinolide T1 (1). The C13-C21 fragment was prepared from two simple starting materials that were joined in a catalytic alkyne-epoxide fragment coupling operation, whereas an intramolecular aldehyde-alkyne reductive coupling simultaneously formed the final carbon-carbon bond of the macrocycle and established the C13 carbinol configuration with complete selectivity in the desired fashion.
Total Syntheses of Amphidinolides T1 and T4 via Catalytic, Stereoselective, Reductive Macrocyclizations
作者:Elizabeth A. Colby、Karen C. O'Brie、Timothy F. Jamison
DOI:10.1021/ja042733f
日期:2005.3.1
Described in this work are totalsyntheses of amphidinolidesT1 and T4 using two nickel-catalyzed reductive coupling reactions of alkynes, with an epoxide in one case (intermolecular) and with an aldehyde in another (intramolecular). The latter was used to effect a macrocyclization, form a C-C bond, and install a stereogenic center with >10:1 selectivity in both natural product syntheses. Alternative approaches
在这项工作中描述的是使用两种镍催化的炔烃还原偶联反应来全合成双腙内酯 T1 和 T4,一种情况下是环氧化物(分子间),另一种情况下是醛(分子内)。后者用于实现大环化,形成 CC 键,并在两种天然产物合成中安装具有 >10:1 选择性的立体中心。研究并讨论了分子间炔-醛还原偶联反应连接关键片段的替代方法;发现大环化(即分子内炔-醛偶联)在几个方面(非对映选择性、产率和合成长度)是优越的。炔烃-环氧化物还原偶联有助于构建对应于两种天然产物分子的大约一半的关键片段。在一种情况下(T4 系列),炔烃-环氧化物偶联在二炔偶联中表现出非常高的位点选择性。还提出了在大环化中观察到的立体选择性模型。