Dedicated to Professor Xiyan Lu on the occasion of his 90th birthday
Published as part of the 50 Years SYNTHESIS – Golden Anniversary Issue
Abstract
The construction of nitrogen-containing molecules remains at the cutting edge of organic synthesis because of its wide application in various areas. Instead of prefunctionalized substrates, using free C–H and N–H bonds in the starting materials can supply a more sustainable avenue to the C–N bond-forming reactions. Compared with the well-developed transition-metal-catalyzed protocols, the strategy of introducing optical or electrical energy into reactions is fantastic and appealing. As a result, visible light or electricity mediated amination transformations have continued to develop over the past several years. In this short review, recent progress of carbon–nitrogen bond-forming reactions based on the oxidative cross coupling between C(sp2, sp3)–H and N–H are summarized.
1 Introduction
2 C(sp2)–H/N–H Oxidative Cross Coupling
2.1 Aryl C(sp2)–H as C Nucleophiles
2.1.1 Azoles as N Nucleophiles
2.1.2 Sulfonamides or Sulfonimides as N Nucleophiles
2.1.3 NH3 as N Nucleophile
2.1.4 Morpholine as N Nucleophile
2.1.5 Diaryl Amines as N Nucleophiles
2.1.6 Primary Amines as N Nucleophiles
2.1.7 Imides as N Nucleophiles
2.1.8 Imines as N Nucleophiles
2.2 Alkenyl C(sp2)–H as C Nucleophiles
2.3 Aldehydic C(sp2)–H as C Nucleophiles
3 C(sp3)–H/N–H Oxidative Cross Coupling
3.1 Benzylic C(sp3)–H as C Nucleophiles
3.2 α-C(sp3)–H as C Nucleophiles
4 Conclusions and Outlook
Key words
oxidative cross coupling - amination - C–H bond functionalization - electrochemistry - photochemistry