Correlation of electronic structure to iron catalyzed C-H bond functionalization

电子结构与铁催化C-H键功能化的相关性

基本信息

批准号：
8945459
负责人：
Theodore A Betley
金额：
$ 32.58万
依托单位：
HARVARD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-08-01 至 2019-03-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Correlation of electronic structure to iron catalyzed C-H bond functionalization In the field of homogenous catalysis, few reports have appeared offering general, chemically mild methods for the introduction of nitrogen- or oxygen-containing functional groups into simple hydrocarbon substrates. The ability to selectively incorporate functionality into unactivated C-H bonds represents a significant advance in converting inexpensive chemical feed stocks (e.g. hydrocarbons) to value-added functional molecules. However, the oxidative substitution of C-H bonds with amines or other functional groups often requires preoxidation of substrate or employs strong chemical oxidants in concert with atom or group transfer processes. A streamlined synthesis for functionalized products (e.g. N-heterocycles) with minimal or complete absence of waste generation would have tremendous impact on the synthesis of fine chemicals and pharmaceuticals. Towards this end, we have synthesized a class of electrophilic complexes featuring transiently-formed, or metastable metal-ligand multiple bonds capable of mediating C-H bond functionalization. Using dipyrrin ligand platforms as truncated models of the porphyrin platform found in P450 hydroxylase enzymes, we have observed reactivity from the ferrous-ligand constructs mirrors their porphyrin analogues. Catalytic C-H bond amination and olefin aziridination have been observed from the reaction of organic azides with simple iron(II) and iron(I) coordination complexes. The iron-catalyzed amination reaction is tolerant to a variety of organic azide precursors and has shown reactivity with a range of organic substrates to form N- heterocyclic products: linear azides can be intramolecularly aminated to form both pyrrolidine and piperidine structures, bearing an array of a-functional groups. The broader scientific impact of the proposed research can be summarized as the following: we will improve our understanding of factors contributing to the promotion of productive C-H bond activation and functionalization, further developing new classes of inorganic/organometallic catalysts to synthesize value-added commodity chemicals via clean reaction routes with minimal waste product.

描述（由适用提供）：电子结构与同质催化领域中铁催化的C-H键功能化的相关性，很少有报道出现了一般性，化学温和的方法，用于将含氮或含氧功能基团引入简单的氢碳底物中。将功能选择性合并到未激活的C-H键中的能力代表了将廉价的化学饲料储备（例如碳氢化合物）转化为增值功能分子的显着进步。但是，与胺或其他官能团的C-H键相替代通常需要与原子或组转移过程一致的底物或员工进行强氧化物的预氧化。对功能化产物（例如N-杂环）的简化合成，最少或完全没有废物产生将对精细化学物质和药品的合成产生巨大影响。为此，我们合成了一类具有瞬时形成或亚稳态的金属配体多键的亲电络合物，能够介导C-H键官能化。使用二吡啶配体平台作为P450羟化酶中发现的卟啉平台的截短模型，我们观察到了来自铁 - 配体构建体的反应性，反映了其卟啉类似物。从有机叠氮化物与简单的铁（II）和铁（I）配位复合物的反应中可以观察到催化C-H键胺和烯烃氮化剂。铁催化的胺化反应对多种有机叠氮化前体耐受性，并且与一系列有机底物显示出反应性，形成了N-杂环产物：线性叠氮化物可以在内部内部意外意外形成吡咯烷胺和哌啶结构，并带有一系列无官能组的阵列。拟议研究的更广泛的科学影响可以总结为以下内容：我们将提高对有助于促进生产性C-H键激活和功能化的因素的理解，并进一步开发新的无机/有机/有机金属催化剂，以合成通过与最小废物产物的清洁反应途径合成增值商品化学品。