Enantioselective Synthesis of γ-Lactams by Lewis Base Catalyzed Sulfenoamidation of Alkenes
作者:Jesse L. Panger、Scott E. Denmark
DOI:10.1021/acs.orglett.9b04347
日期:2020.4.3
A method for the catalytic, enantioselective, intramolecular 1,2-sulfenoamidation of alkenes is described. Lewisbase activation of a suitable sulfur electrophile generates an enantioenriched, thiiranium ion intermediate from a β,γ-unsaturated sulfonyl carboxamide. This intermediate is subsequently intercepted by the sulfonamide nitrogen resulting in cyclization to form γ-lactams. Electron-poor alkenes
The Tandem Heck−Allylic Substitution Reaction: A Novel Route to Lactams
作者:Pedro Pinho、Adriaan J. Minnaard、Ben L. Feringa
DOI:10.1021/ol027169x
日期:2003.2.1
[reaction: see text] A novel route to substituted lactams has been developed using a tandem Heck-allylic substitution reaction. The palladium-catalyzed reaction between omega-olefinic N-tosyl amides and vinylic bromides affords in one step the substituted pyrrolidones and piperidones in 49-82% isolated yield. In addition, it is shown that an N-phenyl amide can act as a nucleophile in intramolecular
Cobalt-Catalyzed Cyclization of Unsaturated <i>N</i>-Acyl Sulfonamides: a Diverted Mukaiyama Hydration Reaction
作者:David M. Fischer、Moritz Balkenhohl、Erick M. Carreira
DOI:10.1021/jacsau.2c00186
日期:2022.5.23
The cycloisomerization of β-, γ-, and δ-unsaturated N-acyl sulfonamides to N-sulfonyl lactams and imidates is reported. This transformation is effected in the presence of a CoIII(salen) catalyst using t-BuOOH or air as the oxidant. The method shows good functional group tolerance (alkyl, aryl, heteroaryl, ether, N-Boc) and furnishes an underexplored class of cyclic building blocks. The strong solvent
报道了β-、γ-和δ-不饱和N-酰基磺酰胺环异构化为N-磺酰基内酰胺和亚胺酸酯。这种转变是在 Co III (salen) 催化剂的存在下使用t -BuOOH 或空气作为氧化剂进行的。该方法显示出良好的官能团耐受性(烷基、芳基、杂芳基、醚、N -Boc),并提供了一类尚未开发的环状结构单元。研究了转化的强溶剂依赖性,并强调了N-磺酰亚胺酯产品类的合成多功能性。