Synthesis of Dispirocyclopentyl-3,3′-bisoxindoles via Domino Cycloaddition Reactions of 4-Dimethylaminopyridinium Bromides with 3-Phenacylideneoxindoles

Molecular diversity of TEMPO-mediated cycloaddition of ketohydrazones and 3-phenacylideneoxindoles

This reaction selectively proceeded via aza-Diels–Alder reaction, [3+2] cycloaddition and ring-opening of oxindole to give diverse spirooxindoles and polysubstituted pyrazoles.

Diastereoselective synthesis of spirocyclic isoxazolo[5,4-c]pyrrolo[2,1-a]isoquinolines via cascade double [3 + 2]cycloadditions

The one-pot base-promoted cascade double [3 + 2] cycloaddition reaction of N-cyanomethylisoquinolinium chloride with (E)-3-arylideneindolin-2-ones and (E)-N-hydroxybenzimidoyl chloride afforded novel polycyclic spiro[indoline-3,8'-isoxazolo[5,4-c]pyrrolo[2,1-a]isoquinolines] in good yields and with high diastereoselectivity. When 4-arylidenepyrazol-3-ones, 2-arylidene-1,3-indanediones and arylidenemalononitriles were employed in the reaction, the corresponding spiro[isoxazolo[5,4-c]pyrrolo[2,1-a]isoquinoline-8,4'-pyrazole], spiro[indene-2,8'-isoxazolo[5,4-c]pyrrolo[2,1-a]isoquinoline], and isoxazolo[5,4-c]pyrrolo[2,1-a]isoquinoline derivatives were also prepared in good yields and with high diastereoselectivty. The relative configurations of the polycyclic spiro compounds were clearly elucidated by determination of fifteen single crystal structures.

Cyclodimerization of 3-phenacylideneoxindolines with amino esters for the synthesis of dispiro[indoline-3,1′-cyclopentane-3′,3″-indolines]

Triethylamine-promoted domino cyclodimerization reaction of 3-phenacylideneoxindolines with amino ester hydrochlorides in acetonitrile afforded substituted dispiro[indoline-3,1′-cyclopentane-3′,3″-indolines] in good yields. The relative configuration of the major diastereoisomers was determined by the X-ray diffraction analysis of three single crystal structures.

Formation of diverse polycyclic spirooxindoles via three-component reaction of isoquinolinium salts, isatins and malononitrile

The triethylamine promoted three-component reaction of N-(4-nitrobenzyl), N-ethoxycarbonylmethylisoquinolinium bromide, isatins and malononitrile in ethanol afforded spiro[indoline-3,2′-pyrrolo[2,1-a]isoquinolines] in good yields and with high diastereoselectivity. The similar reaction of N-cyanomethylisoquinolinium chloride mainly gave complex indolo[2″,3″:2′,3′]pyrrolo[3′,4′:4,5]pyrrolo[2,1-a]isoquinoline derivatives. However, the three-component reaction of N-cyanomethylisoquinolinium chloride, isatins and ethyl cyanoacetate mainly resulted in functionalized spiro[indoline-3,8′-pyrido[2′,3′:4,5]pyrrolo[2,1-a]isoquinolines].

Diastereoselective synthesis of benzo[d]chromeno[3′,4′:3,4]pyrrolo[2,1-b]thiazoles via cycloaddition reaction of benzothiazolium salts with 3-nitrochromenes

Diastereospecific synthesis of benzo[d]chromeno[3′,4′:3,4]pyrrolo[2,1-b]thiazoles via cycloaddition reaction of benzothiazolium salts with 3-nitrochromenes.

A [3 + 2]–[4 + 2]–[3 + 2] cycloaddition sequence of isoquinolinium ylide

A unique [3 + 2]–[4 + 2]–[3 + 2] cycloaddition sequence of isoquinolinium ylide is investigated to afford polycyclic compounds with ten stereogenic centers.

Diastereoselective synthesis of dispiro[indoline-3,1′-cyclobutane-2′,3″-indolines] via visible light catalyzed cyclodimerization of 3-phenacylideneoxindoles

A simple synthetic protocol was developed for the efficient synthesis of functionalized dispiro[indoline-3,1′-cyclobutane-2′,3″-indolines] with high diastereoselectivity. The reaction proceeds by cyclodimerization reaction of 3-phenacylideneoxindoles in the presence of a catalytic amount of photosensitizer Ru(bpy