Copper-catalyzed deaminative alkynylation of secondary amines with alkynes: selectivity switch in the synthesis of diverse propargylamines

Transition-metal catalyzed C-N bond activation has become one of the most promising bond cleavage and formation methods in organic synthesis. This method is still challenging when precise control over the selected C-N bond cleavage between two different C(sp(3))-N bonds in one molecule is required. Herein, we report a time-dependent selective synthesis of two kinds of the propargylamines using the same CuBr2/TBHP catalysis system. Control over the addition of terminal alkynes at different reaction times is essential for the site-selective deamination/alkynylation of secondary amines to obtain the corresponding products in good to excellent yields.

Automated summary

Transition-metal catalyzed C-N bond activation is a promising method for bond cleavage and formation in organic synthesis. This study demonstrates a time-dependent selective synthesis of propargylamines using the CuBr2/TBHP catalysis system, which allows for site-selective deamination/alkynylation of secondary amines. Control over reaction time is critical for obtaining high yields of the desired products.