Propargylation of Diaryl Azo Compounds with Metallic Barium
Selective Propargylation of Diaryl Azo Compounds Using Metallic Barium: A. Yanagisawa, T. Heima, K. Watanabe, S. Haeno
Synlett 2020, 31, DOI: 10.1055/s-0040-1706414
Propargylic amines are useful intermediates in organic chemistry. Furthermore, the propargylamine structural framework can be found in compounds of pharmaceutical value. Building on their interest in Barbier-type chemistry using barium as low-valent metal for performing allylations and benzylations of azo compounds, the group of Professor Akira Yanagisawa from Chiba University (Japan) has now reported a further advancement consisting in the propargylation of diaryl azo compounds, leading to a range of propargylated hydrazines as primary products.
Professor Yanagisawa said: “The employment of metallic barium as the source of barium reagents has enabled the synthesis of various propargylic hydrazines in a regioselective manner; the utility of the propargylated products has been further demonstrated by their transformation into propargylated amines and propargylated biphenylamines through two types of N–N bond cleavage.”