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

 描述(由申请人提供)：电子结构与铁催化的C-H键官能化的相关性在均相催化领域，很少有报道提供一般的、化学上温和的方法将含氮或含氧的官能团引入简单的碳氢化合物底物。选择性地将官能团结合到未活化的C-H键中的能力代表着在将廉价的化学原料(例如碳氢化合物)转化为增值功能分子方面的重大进展。然而，C-H键与胺或其他官能团的氧化取代通常需要底物的预氧化或使用强烈的化学氧化剂来配合原子或基团转移过程。功能化产物(如N-杂环)的流线型合成，几乎不产生或完全不产生废物，将对精细化学品和药物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金属-配体多键的亲电配合物，能够介导C-H键官能化。利用联吡咯配体平台作为P450羟基酶中发现的卟啉平台的截断模型，我们观察到了铁配体结构的反应性反映了它们的卟啉类似物。由有机叠氮化合物与铁(II)和铁(I)的简单配位络合物的反应观察到催化C-H键胺化和烯烃叠氮化反应。铁催化的胺化反应对各种有机叠氮前驱体具有耐受性，并已显示出与一系列有机底物反应生成N-杂环产物的活性：线性叠氮化物可以分子内胺化，形成吡咯烷和哌啶结构，带有一系列a-官能团。拟议研究的更广泛的科学影响可以概括为：我们将提高对促进有效的C-H键活化和官能化的因素的理解，进一步开发新型无机/有机金属催化剂，通过清洁的反应路线以最少的废物合成增值商品化学品。

 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.