Diastereoselective Synthesis of β-Lactam-Oxindole Hybrids Through a Three-Component Reaction of Azetidine-2,3-diones, α-Diazo-oxindoles, and Alcohols Catalyzed by [Rh2(OAc)4]

A diastereoselective three-component reaction for the assembly of succinimide and isatin hybrid molecules with potent anticancer activities

A Rh₂(OAc)₄ catalyzed three-component reaction of vinyl diazosuccinimides with alcohols and isatins has been reported, which provides a practical assess to the direct assembly of succinimide and isatin hybrid molecules in good-to-high yields with excellent stereoselectivity. The antiproliferation activity of these synthesized succinimide and isatin hybrid products has been tested via the CCK8 assay in different cancer cell lines, and compounds 4g (SJSA-1, IC₅₀ = 3.82 μM) and 4r (HCT-116, IC₅₀ = 9.02 μM) exhibit higher anticancer potency than other tested compounds.

Dirhodium(II)/Xantphos-Catalyzed Relay Carbene Insertion and Allylic Alkylation Process: Reaction Development and Mechanistic Insights

Although dirhodium-catalyzed multicomponent reactions of diazo compounds, nucleophiles and electrophiles have achieved great advance in organic synthesis, the introduction of allylic moiety as the third component via allylic metal intermediate remains a formidable challenge in this area. Herein, an attractive three-component reaction of readily accessible amines, diazo compounds, and allylic compounds enabled by a novel dirhodium(II)/Xantphos catalysis is disclosed, affording various architecturally complex and functionally diverse α-quaternary α-amino acid derivatives in good yields with high atom and step economy. Mechanistic studies indicate that the transformation is achieved through a relay dirhodium(II)-catalyzed carbene insertion and allylic alkylation process, in which the catalytic properties of dirhodium are effectively modified by the coordination with Xantphos, leading to good activity in the catalytic allylic alkylation process.

Rh(II)/Ag(I)-Cocatalyzed Three-Component Reaction via SN1/SN1'-Type Trapping of Oxonium Ylide with the Nicholas Intermediate

A Rh(II)/Ag(I)-cocatalyzed three-component reaction of propargylic alcohol-Co₂(CO)₆ complexes with diazo compounds and benzyl alcohols is described, which represents the first trapping process of oxonium ylides with carbocations via the S_N1/S_N1'-type pathway. This transformation provides an efficient approach for construction of dicobalt hexacarbonyl-complexed 3,3-disubstituted oxindoles. Further derivatization of the product, initiated by the deprivation of the dicobalt species, gives the 3,3-disubstituted oxindoles with the ene alkynyl group and the privileged spirooxindole-vinyldihydropyran structure.

Convenient One-Pot Four-Component Synthesis of 6,8-Disubstituted-5,6,7,8-tetrahydropyrimido[4,5-d]pyrimidin-4(3H)-ones via a Triple Mannich Reaction

An efficient and simple one-pot four-component protocol has been developed and performed for the synthesis of 6,8-disubstituted-5,6,7,8-tetrahydropyrimido[4,5-d]pyrimidin-4(3H)-ones, involving a triple Mannich reaction of 6-amino-2-(ethylthio)pyrimidin-4(3H)-one, formaldehyde, primary amines, and alcohols. Secondary amines were also utilised instead of alcohols as Mannich nucleophiles, and a variety of functional groups and electronically varied reaction partners were tolerated. This one-pot reaction facilitated the generation of a library of pyrimido[4,5-d]pyrimidin-4(3H)-ones in very good to excellent yields. The regioselectivity of this reaction was investigated using atomic charge calculations, and spectroscopic data confirmed that the triple Mannich products were 6,8-disubstituted-5,6,7,8-tetrahydropyrimido[4,5-d]pyrimidin-4(3H)-ones rather than the isomeric 3,6-disubstituted-5,6,7,8-tetrahydropyrimido[4,5-d]pyrimidin-4(3H)-ones. The structures of all compounds synthesised using the triple Mannich reaction were confirmed via spectroscopic and elemental analyses. The reaction mechanism was studied and confirmed by isolation of the intermediate.

A highly diastereoselective [5+1] annulation to 2,2,3-trisubstituted tetrahydroquinoxalines via intramolecular Mannich-type trapping of ammonium ylides

A highly diastereoselective [5+1] annulation to 2,2,3-trisubstituted tetrahydroquinoxalines was developed by us.

Rhodium-catalyzed cycloaddition of carbonyl ylides for the synthesis of spiro[furo[2,3-a]xanthene-2,3′-indolin]-2′-one scaffolds

Rh(ii)-catalyzed cycloaddition of 3-diazooxindoles with 2-methyl-2-(4-methylpent-3-en-1-yl)-2H-chromene-3-carbaldehydes has been developed to produce tetrahydro-3H,4H-spiro[furo[2,3-a]xanthene-2,3′-indolin]-2′-ones in good yields.

Investigation of the Passerini and Ugi reactions in β-lactam aldehydes. Synthetic applications

Ugi and Passerini multicomponent reactions on 4-oxoazetidine-2-carboxaldehydes allow the straightforward synthesis of highly functionalized β-lactams.

Palladium-catalyzed asymmetric [3+2] cycloaddition to construct 1,3-indandione and oxindole-fused spiropyrazolidine scaffolds

A facile and versatile Pd/L8-catalyzed asymmetric [3+2] cycloaddition of 3-diazooxindoles with a new vinylcyclopropane to construct spiropyrazolidine derivatives has been developed.

Rhodium-catalyzed three-component reaction of 3-diazooxindoles with indoles and isatin-derived ketimines: a facile and versatile approach to functionalized 3,3′,3′′-trisindoles

A variety of functionalized 3,3′,3′′-trisindoles could be produced in high yields with moderate to excellent diastereoselectivities via Rh₂(OAc)₄-catalyzed three-component reaction of 3-diazooxindoles with indoles and isatin-derived N-Boc ketimines.