Synfacts 2011(3): 0327-0327  
DOI: 10.1055/s-0030-1259446
Organo- and Biocatalysis
© Georg Thieme Verlag Stuttgart ˙ New York

Base-Catalyzed Synthesis of 1,2,4-Triazolines

Contributor(s): Benjamin List, Lars Ratjen
D. Monge, K. L. Jensen, I. Marín, K. A. Jørgensen*
Aarhus University, Denmark
Further Information

Publication History

Publication Date:
16 February 2011 (online)

Significance

The authors report a base-catalyzed hydrazination-cyclization sequence for the one-pot synthesis of highly substituted 1,2,4-tri­azolines. The scope of the reaction proved to be very general regarding the azodicarboxylates and α-isocyano esters/amides. Even the base could be switched from nitrogen-containing structures to Ph3P, probably to a mechanism, which involves a Huisgen zwitterion intermediate. Furthermore, initial attempts towards an asymmetric version of the ­reaction are reported, using cinchonine-­derived catalysts under phase-transfer conditions.