Facile One-Pot Coupling−Aminovinylation Approach to Push−Pull Chromophores: Alkyne Activation by Sonogashira Coupling
摘要:
A straightforward coupling-aminovinylation sequence of terminal alkynes 1, electron-deficient heteroaryl halides 2, and secondary amines 4 furnishes highly solvochromic push-pull chromophores 5 in good yields. Semiempirical calculations (PM3) suggest that the aminovinylation proceeds in a stepwise fashion through a zwitterionic intermediate with a final rate-determining intramolecular protonation. Crucial parameters for the success of the amine addition are the relative LUMO energies and the charge distribution at the beta-alkynyl carbon atom.
Facile One-Pot Coupling−Aminovinylation Approach to Push−Pull Chromophores: Alkyne Activation by Sonogashira Coupling
作者:Alexei S. Karpov、Frank Rominger、Thomas J. J. Müller
DOI:10.1021/jo026470o
日期:2003.2.1
A straightforward coupling-aminovinylation sequence of terminal alkynes 1, electron-deficient heteroaryl halides 2, and secondary amines 4 furnishes highly solvochromic push-pull chromophores 5 in good yields. Semiempirical calculations (PM3) suggest that the aminovinylation proceeds in a stepwise fashion through a zwitterionic intermediate with a final rate-determining intramolecular protonation. Crucial parameters for the success of the amine addition are the relative LUMO energies and the charge distribution at the beta-alkynyl carbon atom.