Photoredox Catalysis in Organic Chemistry

有机化学中的光氧化还原催化

基本信息

批准号：
9277495
负责人：
David W MacMillan
金额：
$ 30.42万
依托单位：
PRINCETON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-04-01 至 2018-05-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Over the past five years, visible light-mediated photoredox catalysis has emerged as a versatile new activation platform in organic synthesis. Ruthenium or iridium-based polypyridyl photoredox catalysts absorb light in the visible range to generate stable, long-lived excited states that may act as either single-electron oxidants or reductants. Due to their unique reactivity profile, photoredox catalysts have the capacity to enable challenging bond constructions that are not accessible under standard approaches. In a seminal 2008 disclosure, our lab described the asymmetric α-alkylation of aldehydes via the synergistic merger of photoredox catalysis and chiral amine organocatalysis; this powerful dual-catalysis strategy features the simultaneous generation of catalytic quantities of both reactive intermediates. Subsequent reports, from our group and others, have further established the remarkable complexity-building capabilities of photoredox catalysis, particularly when merged with organocatalysis. In this research proposal, we outline new directions for our photoredox-based research program. Each of the four aims proposed herein envisions a novel reactivity platform featuring a transient, photoredox-generated active species that may be productively harnessed for the synthesis of a menu of high-value functional motifs. In Aim 1, we propose to develop direct, one-carbon expanded variants of the Mannich, Michael, and aldol reactions via a novel 5π-electron intermediate species that is transiently generated from ketone or aldehyde precursors through synergistic organocatalysis and photoredox catalysis. Aim 2 leverages an α-amino radical species - generated in situ via photoredox catalysis - en route to valuable amine-containing scaffolds, including vicinal diamines and allylic amines. Aim 3 envisions the direct arylation of labile allylic and benzylic C-H bonds through synergistic thiol-based organocatalysis and photoredox catalysis, as a means by which to gain rapid access to diaryl methanes and vinyl-aryl methanes. Finally, in Aim 4, we propose to accomplish the photoredox-catalyzed decarboxylative functionalization of α-amino acids en route to valuable benzylic amine and alkyl amine motifs. In a key expansion of this project, we will explore opportunities for the development of an asymmetric variant for the synthesis of γ-amino aldehydes via merged photoredox and chiral amine-based organocatalysis.

描述（由适用提供）：在过去的五年中，可见光介导的光介毒催化已成为有机合成中多功能的新激活平台。基于ruthenium或基于虹膜的多吡啶基光电氧催化剂在可见范围内吸收光，以产生稳定的，长寿的激发态，可以充当单电子氧化物或还原。由于其独特的反应性概况，Photoredox催化剂具有使无法理解标准方法的挑战键结构的能力。在2008年的第二次披露中，我们的实验室通过光毒素催化和手性胺有机催化的协同合并描述了醛对醛的不对称α-烷基化。这种强大的双分解策略具有同时产生两种反应性中间体的催化量。随后的报道，来自我们小组和其他人，进一步建立了光电毒素催化的显着复杂性建设能力，尤其是当与有机催化合并时。在这项研究建议中，我们概述了基于Photoredox的研究计划的新方向。本文提出的四个目标中的每个目标都设想了一个新型的反应性平台，其具有短暂的，光电氧化的活性物种，可以有效地利用高价值功能基序的菜单。在AIM 1中，我们提出的是AIM 2利用α-氨基自由基物种 - 通过光电毒素催化作用 - 在原位生成 - 在有价值的含胺的支架（包括替代性二氨基和烯丙基胺）的途径中。设想通过基于硫醇的有机催化和光电毒素催化的不稳定垂直抗原和苯二氧化物C-H键，这是一种能够快速获取日记甲烷和乙烯基 - 芳基甲烷的手段。最后，在AIM 4中，我们建议完成光电毒素催化的脱羧功能 α-氨基酸在通往有价值的苄基胺和烷基胺基序的途径中。在该项目的关键扩展中，我们将通过合并的光毒素和基于手性胺的有机催化来探索开发不对称变体的机会。