Organometallic reactions characteristic of chiral heterocyclic compounds: Synthesis and stereoselective grignard reaction of chiral 4-Oxa-7,7a-diazaperhydroindans.
Asymmetric synthesis of 1-substituted tetrahydroisoquinolines by nucleophilic addition to hydrazonium ions. Application to the enantioselective syntheses of (+)- and (−)-salsolidines and (−)-cryptostyline II
作者:Hideaki Suzuki、Sakae Aoyagi、Chihiro Kibayashi
DOI:10.1016/00404-0399(50)1358-o
日期:1995.9
hydride reagents to hydrazonium salts modified by optically active 2-substituted pyrrolidine auxiliaries leads to highly enantioselectivesynthesis of 1-substitutedtetrahydroisoquinolines. This methodology was applied to asymmetric synthesis of the title isoquinoline alkaloids.
Organocerium additions to proline-derived hydrazones: synthesis of enantiomerically enriched amines
作者:Scott E. Denmark、James P. Edwards、Theodor Weber、David W. Piotrowski
DOI:10.1016/j.tetasy.2010.04.042
日期:2010.5
The addition of organocerium reagents (from both organolithium and organomagnesium precursors) to chiral aldehyde hydrazones prepared from 1-aminoproline derivatives has been studied. The additions proceed in good yield and high diastereoselectivity and with good nucleophile (Me, n-Bu, i-Pr, t-Bu, Ph, etc.) and substrate scope (alkyl, alkenyl and aryl). The resulting hydrazines can be converted to
Organometallic reactions characteristic of chiral heterocyclic compounds: Synthesis and stereoselective grignard reaction of chiral 4-Oxa-7,7a-diazaperhydroindans.
New heterocyclic compounds, 6-phenyl-4-oxa-7, 7a-diazaperhydroindans (5 and 6), were synthesized by condensation of chiral 2-hydroxyethylhydrazines prepared from (R)-phenylglycinol with γ-chlorobutyraldehyde. The stereoselective Grignard reaction of 5 and 6 proceeded to give chiral 2-substituted 1-[N-(2-hydroxy-1-phenylethyl)amino] pyrrolidines(7a-d and 8a-d). The structures of these products were determined by comparison with authentic samples, and the reaction mechanism is proposed to involve an intermediate iminium salt.