Enantioselective Total Syntheses of Welwitindolinone A and Fischerindoles I and G
摘要:
The first total syntheses of welwitindolinone A and the most complex members of the fischerindole family, fischerindoles I and G, are reported. Highlights of these short, protecting-group-free syntheses include the application of the recently developed direct indole-carbonyl coupling, a simple approach for installing the quaternary center with neighboring chlorine atom, a regioselective dehydrogenation/dehydration cascade to access fischerindole I, and a remarkably facile oxidative ring contraction to construct welwitindolinone A. An alternative biogenetic hypothesis, whose accuracy is suggested by the success of the current syntheses, is also put forth for this alkaloid family.
Enantiospecific Total Synthesis of the Hapalindoles, Fischerindoles, and Welwitindolinones <i>via</i> a Redox Economic Approach
作者:Jeremy M. Richter、Yoshihiro Ishihara、Takeshi Masuda、Brandon W. Whitefield、Tomás Llamas、Antti Pohjakallio、Phil S. Baran
DOI:10.1021/ja806981k
日期:2008.12.31
the total synthesis of several members of the hapalindole family of naturalproducts, including hapalindole Q, 12-epi-hapalindole D, 12-epi-fischerindole U, 12-epi-fischerindole G, 12-epi-fischerindole I, and welwitindolinone A. Use of the recently developed direct indole coupling enabled an efficient, practical, scalable, and protecting-group-free synthesis of each of these naturalproducts. The original
提供了天然产物 hapalindole 家族几个成员的全合成的完整细节,包括 hapalindole Q、12-epi-hapalindole D、12-epi-fischerindole U、12-epi-fischerindole G、12-epi-fischerindole I , 和 welwitindolinone A. 使用最近开发的直接吲哚偶联能够高效、实用、可扩展且无保护基团合成这些天然产物中的每一种。审查了最初的生物合成提案,并提出了修改后的生物合成假设,并通过上述合成进行了验证。合成的特征还在于坚持“氧化还原经济”的概念。类似于“原子经济”或“阶梯经济”,“氧化还原经济”最大限度地减少了合成中多余的氧化还原操作;相当,
Enantioselective Total Syntheses of Welwitindolinone A and Fischerindoles I and G
作者:Phil S. Baran、Jeremy M. Richter
DOI:10.1021/ja056171r
日期:2005.11.1
The first total syntheses of welwitindolinone A and the most complex members of the fischerindole family, fischerindoles I and G, are reported. Highlights of these short, protecting-group-free syntheses include the application of the recently developed direct indole-carbonyl coupling, a simple approach for installing the quaternary center with neighboring chlorine atom, a regioselective dehydrogenation/dehydration cascade to access fischerindole I, and a remarkably facile oxidative ring contraction to construct welwitindolinone A. An alternative biogenetic hypothesis, whose accuracy is suggested by the success of the current syntheses, is also put forth for this alkaloid family.