An improved synthesis of some 5-substituted indolizines using regiospecific lithiation.
Various 2-substituted indolizines can be directly and selectively lithiated in the 5 position and subsequent reactions with different electrophiles lead to some novel classes of indolizines. In particular, previously unknown 5-formyl- and 5-iodoindolizine have been prepared by this way and the molecular structure of 5-formyl-2- phenylindolizine was confirmed by X-Ray analysis. The reactivity of the 5-CHO- and 5- COPh groups toward some nucleophiles has been examined, and some additional classes of derivatives (oximes and alcohols) have been obtained. The possibility of Suzuki cross- coupling of 5-iodoindolizines and boronic acids was proven.
Kuznetsov
Alexey G
AG
Chemistry Department, Moscow State University, Moscow 119992, Russia.
Bush
Alexander A
AA
Rybakov
Viktor B
VB
Babaev
Eugene V
EV
D007212:Indolizines / Q000138:chemical synthesis* / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D011522:Protons; D013237:Stereoisomerism
D007212:Indolizines; D011522:Protons; D008094:Lithium