The first catalytic asymmetric exo′‐selective [3+2] cycloaddition of methyleneindolinones with iminoesters was achieved for construction of novel diastereomers of spiro[pyrrolidin‐3,3′‐oxindole]. By using the imidazoline–aminophenol‐ligand complex [Ni(OAc)2–(L1)], the reaction proceeds in the stepwise Michael–Mannich reaction to give the exo′ adducts as stable isomers (see scheme).
A Facile Method for the Synthesis of 3-Alkyloxindole
作者:Tai-Ping Du、Gang-Guo Zhu、Jian Zhou
DOI:10.2174/157017812800167420
日期:2012.3.1
Benzylamine in combination with acetic acid was identified as a powerful catalyst for the condensation of oxindole with aldehydes, acetone or cyclic ketones. A variety of 3-alkyloxindoles could be readily prepared in 10 mmol scale via the sequential benzylamine acetate catalyzed condensation of oxindoles with aldehydes (or ketones) and conjugate reduction by NaBH4.
An enantioconvergent substitution of 3-substituted 3-chlorooxindoles with N-aryl glycines under visible light irradiation is reported. A transition-metal-free cooperative catalysis platform with a dicyanopyrazine-derived chromophore (DPZ) as a photoredox catalyst and a chiral Brønsted acid catalyst is effective for these transformations, which involve a single-electron transfer redox step and an enantioselective
Construction of indeno[1,2-<i>a</i>]fluorene <i>via</i> domino reaction of 1,3-indanedione and 3-arylideneindolin-2-ones or chalcones
作者:Jun Cao、Jing Sun、Chao-Guo Yan
DOI:10.1039/c9ob01779h
日期:——
the base promoted domino reaction of 1,3-indanedione with 3-arylideneindolin-2-ones. The domino reaction in different solvents selectively gave carbamato- or amino-substituted indeno[1,2-a]fluorene in satisfactory yields. Additionally, a similar domino reaction of 1,3-indanediones with chalcones also gave polysubstituted indeno[1,2-a]fluorenes in high yields. The reaction mechanism is believed to proceed
PyBidine-Cu(OTf)<sub>2</sub>-Catalyzed Asymmetric [3+2] Cycloaddition with Imino Esters: Harmony of Cu-Lewis Acid and Imidazolidine-NH Hydrogen Bonding in Concerto Catalysis
(PyBidine)–Cu(OTf)2 complex catalyzing the endo‐selective [3+2] cycloaddition of nitroalkenes with imino esters was applied to the reaction of methyleneindolinones with imino esters to afford spiro[pyrrolidin‐3,3′‐oxindole]s in up to 98 % ee. X‐ray crystallographic analysis of the PyBidine–Cu(OTf)2 complex and DFT calculations suggested that an intermediate Cu enolate of the imino ester reacts with