Transition-metal free C-N bond formation from alkyl iodides and diazonium salts via halogen-atom transfer

Construction of C-N bond continues to be one part of the most significant goals in organic chemistry because of the universal applications of amines in pharmaceuticals, materials and agrochemicals. However, E2 elimination through classic S(N)2 substitution of alkyl halides lead to generation of alkenes as major side-products. Thus, formation of a challenging C(sp(3))-N bond especially on tertiary carbon center remains highly desirable. Herein, we present a practical alternative to prepare primary, secondary and tertiary alkyl amines with high efficiency between alkyl iodides and easily accessible diazonium salts. This robust transformation only employs Cs2CO3 promoting halogen-atom transfer (XAT) process under transition-metal-free reaction conditions, thus providing a rapid method to assemble diverse C(sp(3))-N bonds. Moreover, diazonium salts served as alkyl radical initiator and amination reagent in the reaction. Mechanism studies suggest this reaction undergo through halogen-atom transfer process to generate active alkyl radical which couples with diazonium cations to furnish final products. The pursuit of efficient C-N bond formation is a prime focus of synthetic organic chemistry. Here, the authors documented a base promoted amination between alkyl iodides and diazonium salts via halogen-atom transfer (XAT) process.

Automated summary

The construction of C-N bonds is of great significance in organic chemistry due to the wide applications of amines. This study presents a practical and efficient method for the synthesis of alkyl amines by using alkyl iodides and diazonium salts. The reaction proceeds through a halogen-atom transfer process, providing a rapid approach for the formation of diverse C(sp(3))-N bonds.