24445-35-0Relevant articles and documents
Synthesis of 3,4-diarylpyrroles and conversion into dodecaarylporphyrins; a new approach to porphyrins with altered redox potentials
Ono, Noboru,Miyagawa, Hirokazu,Ueta, Takahiro,Ogawa, Takuji,Tani, Hiroyuki
, p. 1595 - 1601 (2007/10/03)
3,4-Diarylpyrroles (1) have been directly prepared in 20-50% yield by the reaction of β-nitrostyrenes with aqueous TiCl3 in 1,4-dioxane. Pyrroles 1 were also prepared via Barton-Zard pyrrole synthesis using the reaction of α-nitrostilbenes with ethyl isocyanoacetate followed by de-ethoxycarbonylation. 3,4-Diarylpyrroles have been converted into dodecaarylporphyrins by reaction with aromatic aldehydes. Various aryl groups are readily introduced at the periphery of porphyrins by this method. Phenyl substitution at any of the positions of pyrroles decreases E1/2ox while E1/2red is almost unchanged. On the other hand, substitution of the 2-thienyl group affects both the HOMO and LUMO energies, and the UV-vis spectra of dodeca-2-thienylporphyrins (4f or 4i) are extremely red-shifted.
CHEMOSELECTIVE PROTECTION OF HETEROAROMATIC ALDEHYDES AS IMIDAZOLIDINE DERIVATIVES. PREPARATION OF 5-SUBSTITUTED FURAN- AND TIOPHENE-2-CARBOXALDEHYDES VIA METALLO-IMIDAZOLIDINE INTERMEDIATES
Carpenter, Andrew J,,Chadwick, Derek J.
, p. 3803 - 3812 (2007/10/02)
Furan-, tiophene- and N-methylpyrrole-2-carboxaldehydes may be transformed into the corresponding N,N'-dimethylimidazolidines in a reaction not requiring acid catalysis.The resulting furan and tiophene (but not N-methylpyrrole) derivatives may be metallated in high yields and the carboxaldehyde functionality regenerated under very mild conditions.Treatment of the aldehydoketone 2-acetyl-5-formylthiophene with N,N'-dimethylethylenediamine gives only the product of reaction at the aldehyde function thus establishing this methodology as a potentially valuable method for the protection of an aldehyde in the presence of a ketone.
