One-Pot Synthesis of Pyrrole-2-carboxylates and -carboxamides via an Electrocyclization/Oxidation Sequence
作者:Dennis Imbri、Natalie Netz、Murat Kucukdisli、Lisa Marie Kammer、Philipp Jung、Annika Kretzschmann、Till Opatz
DOI:10.1021/jo5021823
日期:2014.12.5
An electrocyclic ring closure is the key step of an efficient one-pot method for the synthesis of pyrrole-2-carboxylates and -carboxamides from chalcones and glycine esters or amides. The 3,4-dihydro-2H-pyrrole intermediates generated in situ are oxidized to the corresponding pyrroles by stoichiometric oxidants or by catalytic copper(II) and air in moderate to high yields. A wide range of functional groups are tolerated, and further combination with an in situ bromination gives access to polyfunctional pyrrole scaffolds.
Modular De novo Synthesis of Unsymmetrical BODIPY Dyes Possessing Four Different Aryl Substituents
Unsymmetrical BODIPY dyes carrying four aryl moieties in positions 1, 3, 5, and 7 can be assembled in a modular fashion from pyrrole building blocks individually produced in two separate [6π] electrocyclizations. The method uses benzaldehydes, acetophenones, and glycine nitrile or glycine ethyl ester as the starting materials.