Tandem aldehyde–alkyne–amine coupling/cycloisomerization: A new synthesis of coumarins

• Maddi Sridhar Reddy,
• Nuligonda Thirupathi and
• Madala Haribabu

Beilstein J. Org. Chem. 2013, 9, 180–184, doi:10.3762/bjoc.9.21

• moderate yields. Keywords: A3 coupling; cooperative catalysis; coumarin synthesis; cycloisomerization; transition-metal catalysts; Introduction An alkyne, an aldehyde and an amine coupling, referred to as A3 coupling [1], has been found as an efficient method for C–N and C–C bond formation that results

Cyclization of ortho-hydroxycinnamates to coumarins under mild conditions: A nucleophilic organocatalysis approach

• Florian Boeck,
• Max Blazejak,
• Markus R. Anneser and
• Lukas Hintermann

Beilstein J. Org. Chem. 2012, 8, 1630–1636, doi:10.3762/bjoc.8.186

• developing new solutions to synthetic problems. Experimental General procedure for coumarin synthesis The starting hydroxycinnamate ester (1 mmol) was inserted in a headspace vial containing a magnetic stirring bar. The vial was flushed with argon and capped. Methanol (1 mL, degassed with argon) was added by