摘要
酰胺基团常见于天然产物和药物分子中,利用它们的导向作用完成其普通烷烃C—H键的选择性功能化的相关反应研究在近十年内已取得迅速发展,并且这类反应也将逐渐成为构筑分子骨架、延长碳链和引入官能团的理想方法.本文对过去十年该领域的进展按成键形式、反应物类型分类并以时间顺序排列,依次叙述生成烷烃芳烃、烷烃烯烃、烷烃羰基、烷烃炔烃及烷烃烷烃结构的碳碳键和碳氮、碳氧等碳杂原子键的反应.论述主要集中在反应的表现、改进及其合成应用,以及反应机理讨论等.
Normal alkyl C—H bonds refer to those sp^3 C—H bonds not linking with any carbon functional groups or heteroatoms at their adjacent positions. They are fundamental chemical bonds, which are widespread both in raw materials such as petroleum oil, natural gas etc. for chemical industries and in various kinds of intermediates for chemical syntheses. Selective transformation of these ubiquitous alkyl C—H bonds into new carbon-carbon, carbon-nitrogen, or carbon-oxygen bonds is an ideal method in construction of molecular skeletons, extension of carbon-chains and introduction of functional groups, which is urgently desired in either large-scale production or laboratory synthesis. However, these normal sp^3 C—H bonds are extremely chemical inert, due to their high bond dissociation energy and low acid dissociation constant. Thus, they are not used directly and conveniently as other available functional groups in synthetic chemistry. Since the beginning of this century, the functionalization of normal alkyl C—H bonds has been developed rapidly through C—H activation which is to cleave these inert C—H bonds with the assistance of some special directing groups by use of catalytic transition-metal complexes under mild conditions. Amides as one of the effective directing groups, which are prevalent in natural products and pharmaceuticals, has also received particular attention. A series of novel reactions using various amides as directing groups to produce carbon-carbon and carbon-heteroatom bonds, including alkyl-aryl, alkyl-alkenyl, alkyl-carbonyl, alkyl-alkynyl, alkyl-alkyl linkages and carbon-nitrogen, carbon-oxygen, carbon-chlorine, carbon-bromine, carbon-boron, carbon-sulfur, carbonselenium bonds, etc. have been established, and some of them have been applied to the practical synthesis already. This review describes the development on the functionalization of normal alkyl C—H bonds according to the formed bonds, reaction substrates, and chronological order. It is emphasized that the structures of amide groups, properties of transition metals, regional and stereo-selectivities in C—H activations, reaction mechanisms, subsequent transformations and their synthetic applications, etc.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2015年第12期1250-1274,共25页
Acta Chimica Sinica
基金
国家自然科学基金(No.21372153)资助~~
关键词
C—H键活化
烷烃
功能化
酰胺
导向基团
C—H activation
alkane
functionalization
amide
directing group
