New and clean synthesis of N-substituted pyrroles under microwave irradiation
N-Substituted homochiral pyrrole derivatives were synthesized by the ring-closure reaction of cis-1,4-dichloro-2-butene with various amine compounds on a silica surface under microwave irradiation.
Aydogan, Feray,Basarir, Mehmet,Yolacan, Cigdem,Demir, Ayhan S.
p. 9746 - 9750
(2008/02/12)
Intermolecular one-pot cyclization of formyl-pyrroles of amino acid esters with norephedrine: stereoselective routes to new tricyclic pyrrole-pyrazine-oxazole fused structures
The treatment of esters of amino acids with dimethoxytetrahydrofuran furnished pyrrole derivatives of amino acid esters. The Wilsmeier-Haack formylation followed by the reaction of the formylated pyrroles with norephedrine afforded a selective formation of the tricyclic pyrrole-pyrazine-oxazole fused structures in one step via the formation of an oxazoline structure and intramolecular lactam formation. Pyrrole-pyrazine-oxazole fused structures were achieved in good yields. The cyclization reaction for the formation of an oxazole ring worked selectively to form only one stereoisomer. The configuration of the newly generated stereogenic center in the oxazole ring is dependent on the stereogenic centers of norephedrine.
Demir, Ayhan S.,Subasi, N. Tuna,Sahin, Ertan
p. 2625 - 2631
(2007/10/03)
A new class of optically active pyrrole derivatives: (3R)-3-(pyrrol-1-yl)alk-1-enes from D-α-aminoacids
(3R)-3-(Pyrrol-1-yl)but-1-ene 4a, (3R)-4-methyl-3-(pyrrol-1-yl)pent-1-ene 4b, (3R)-3-(pyrrol-1-yl)hex-1-ene 4c in high enantiomeric excess (>92%) were prepared starting from D-α-amino acids. The crucial steps in the synthesis, reduction (DIBAH) of the corresponding pyrrolylesters to the corresponding pyrrolylaldehydes followed by Wittig olefination proceeded without compromising the stereochemical integrity.