18159-10-9Relevant academic research and scientific papers
Total synthesis of heronapyrrole C
Ding, Xiao-Bo,Furkert, Daniel P.,Capon, Robert J.,Brimble, Margaret A.
supporting information, p. 378 - 381 (2014/04/03)
A flexible total synthesis of the 2-nitropyrrole-derived marine natural product, (+)-heronapyrrole C, is reported. The approach is based on regioselective access to key building blocks containing the rare 4-substituted 2-nitropyrrole motif. Sharpless asymmetric epoxidation and dihydroxylation and a Shi epoxidation were used to introduce the five stereogenic centers of the bis-THF-diol side chain. The N-benzoyloxymethyl (Boz) protecting group was crucial for functionalization of the 2-nitropyrrole moiety and enabling final deprotection under mild conditions.
ALKYLATION ORIENTATION RULES IN CONJUGATE ADDITION OF GRIGNARD REAGENTS TO NITROPYRROLE AND NITROTHIOPHENE SYSTEMS
Ballini, Roberto,Bartoli, Giuseppe,Bosco, Marcella,Dalpozzo, Renato,Marcantoni, Enrico
, p. 6435 - 6440 (2007/10/02)
Conjugate addition of various Grignard reagents to 1-alkyl-2-nitropyrroles and to 2-nitrothiophene has been investigated. 1-Alkyl-2-nitropyrroles undergo alkylation at 3 and 5 positions with prevalence of the latter isomer.On the contrary, in the 2-nitrothiophene system, formation of the 3-isomer prevails.In both systems, a bulkier Grignard reagent favours the 5-isomer formation.This trend can be reversed increasing steric hindrance exerted by the 1-substituent of 2-nitropyrrole. 1-(Tri-isopropylsilyl)-3-nitropyrrole and 3-nitrothiophene give exclusively the 2-isomer.This reaction allows 2-alkyl-3-nitrothiophenes and pyrroles to be synthesized with a one-pot procedure instead of the classical multi stage reaction.
