EaStCHEM, School of Chemistry, University of St. Andrews, North Haugh, St. Andrews, U.K., KY16 9ST.
Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, U.K.
Org Lett. 2022 Jul 29;24(29):5444-5449. doi: 10.1021/acs.orglett.2c02170. Epub 2022 Jul 18.
Enantioselective [2 + 2] cycloaddition of C(1)-ammonium enolates generated catalytically using the isothiourea HyperBTM with -alkyl isatins gives spirocyclic β-lactones. ring opening with an amine nucleophile generates isolable highly enantioenriched products in up to 92:8 dr and in >99:1 er.
使用异硫脲 HyperBTM 催化生成的 C(1)-铵烯醇化物的对映选择性 [2 + 2] 环加成反应与 - 烷基靛红反应,得到螺环β-内酰胺。用胺亲核试剂进行开环反应,可得到高达 92:8 dr 和 >99:1 er 的可分离的高对映过量产物。