<i>N-</i>Pyrrolylketene: A Nonconjugated Heteroarylketene
作者:Mohammad Reza Islami、Annette D. Allen、Sinisa Vukovic、Thomas T. Tidwell
DOI:10.1021/ol102837n
日期:2011.2.4
preferred geometry with the pyrrolyl ring orthogonal to the ketenyl group. Ketene 5 is generated from N-pyrrolylacetic acid (7) with use of Mukaiyama’s reagent, and reacts with imines forming β-lactams 10, with a product ratio correlation of log(cis/trans) with σ+. Photolysis of N-diazoacetylpyrrole (14) in MeOH gives methyl N-pyrrolylacetate (15) from 5 and also ester 17, evidently by trapping of
A Novel Asymmetric Synthesis of 3-(1H-Pyrrol-1-yl)-Substituted β-Lactams via a Bismuth Nitrate-Catalyzed Reaction
作者:Aarif L. Shaikh、Bimal K. Banik
DOI:10.1002/hlca.201100202
日期:2012.5
The reaction of racemic α‐keto β‐lactams 5a–5c with the commercially available chiral compound trans‐4‐hydroxy‐L‐proline (6) in the presence of a catalytic amount of Bi(NO3)3⋅5 H2O in EtOH gave a diastereoisomer mixture of β‐lactams with a pyrrole ring at C(3) (7 to 12). This is the first enantioselective synthesis of opticallyactive β‐lactams (=azetidin‐2‐ones) that possess a pyrrolyl residue at