An Efficient Synthesis of (±)-4-Amino-3-(4-chlorophenyl)-butyric Acid. (Baclofen)
作者:Toshiro Ibuka、An[ggrave]ele Schoenfelder、Patricia Bildstein、Andre Mann
DOI:10.1080/00397919508015419
日期:1995.6
Abstract A new preparation of baclofen is proposed. The key step involved a regioselective ring opening of 2-phenylaziridine with allylmagnesium bromide. Further oxydation of the side chain give access to 4-phenyl-pyrrolidin-2-one and to baclofen.
N-tosyl phenylaziridines are opened regioselectively with allylsilanes in presence of BF3.Et2O to form γ-amino olefins. During the reaction a formal [3+2] cycloaddition produced the corresponding pyrrolidines, amenable to the open chain compounds with TBAF.
Palladium-catalyzed highly selective intramolecular bromoamination of alkenes: Efficient synthesis of substituted pyrrolidines
作者:Jingfang Zhang、Xie Wang、Yulong Liu、Xiaoyun Wang、Wei He
DOI:10.1002/aoc.3631
日期:2017.6
A new method has been developed for the preparation of substituted pyrrolidines by the palladium‐catalyzed intramolecular bromoamination of substituted aminoalkenes. The catalytic system and reaction conditions used for this transformation have been fully optimized. Notably, this reaction exhibits excellent selectivity, affording the pyrrolidine products as single 5‐exo‐bromoalkylpyrrolidines in excellent
Phenyl aziridines undergo 1,3-dipolar cycloaddition efficiently with olefins such as cyclic enol ethers and allyltrimethylsilane in the presence of a catalytic amount of Sc(OTf)3 at ambient temperature to afford the corresponding pyrrolidine derivatives in high yields with high regioselectivity.
A nickel-catalyzed reductive cross-coupling of aziridines and allylicchlorides was realized by using manganese metal as the reducing agent. This protocol afforded a convenient approach to obtain β-allyl-substituted arylethylamines bearing various functional groups. The utility of this reaction was also demonstrated by scale-up preparation and diverse transformations, including the synthesis of Baclofen