Spirocyclische 2‐Indolinone durch 1,3‐dipolare Cycloaddition

Abstract

Die Synthese von Spiro[indolin-3,3'-[l]pyrazolin]-2-onen 3, Spiro[indolin-3,1'-cyclopropan]-2-onen 6, Spiro[indolin-3,5'-und Spiro[indolin-3,4'-[2]isoxazolin]-2-onen 8 bzw. 9 sowie Spiro[indolin-3,5'-[Az-l,2,4]oxadiazolin]-2-onen 11 durch 1,3-dipolare Cycloadditionen von Diazoalkanen und Benzonitriloxid an 2-Oxindolin-3-ylidenessigsaureester und Isatin-p-anile wird beschrieben. Spirocyclic 2-Indolinones by 1,3-DipoImr Cycloaddition The synthesis of spiro[indoline-3,3'-[l]pyrazolin]-2-ones 3, spiro[indoline-3,1'-cyclopropan]-2ones 6, spiro[indoline-3,5'-and spiro[indoline-3,4'-[2]isoxazolin]-2-ones 8 and 9, respectively, and spiro[indoline-3,5'-[A2-1,2,4]oxadiazolin]-2-ones 11 by 1,3-dipolar cycloaddition of diazoalkanes and benzonitrile oxide to 2-oxindolin-3-ylideneacetic esters and isatin-p-anils is described.

The Three‐Component Reaction between Isatin, α‐Amino Acids, and Dipolarophiles

“…Larger dipolarophiles, such as chalcones, have been used successfully in this three-component reaction. [13] When ethyl (3-methyleneoxindole)acetate [14] was used as the dipolarophile in the decarboxylative condensation between isatin (5) and N-benzylglycine (6b), we obtained the doublespiro compound 11 that has the same configuration as some related molecules (e.g., 12) that were reported by Casaschi et al [15] Eur. J.…”

Stereoselective Synthesis of Tetrahydroindolizines through the Catalytic Formation of Pyridinium Ylides from Diazo Compounds

“…[26] Similar pyrazoles have been reported to contract to cyclopropanes upon heating, [28][29][30] but this possibility was ruled out when starting materials were returned upon subjecting spiropyrazole 25 to 3-bromopyridine and Fe(TPP)Cl (10 mol%) in toluene at room temperature. Cyclopropanes could also undergo non-catalysed ring expansion with pyridine, [31,32] but only starting materials were obtained from reaction of cyclopropane 3 using the latter reaction conditions.…”

The chemistry of isatins: a review from 1975 to 1999

“…In non-substituted acrylates, the 1,3-dipolar cycloaddition occurs furnishing a pyrazoline which, upon heating, losses N 2 to give a spiro cyclopropane derivative 462,463 . If acyanoacrylates are used, the cyano group reverses the polarization of the C-C double bond, and the diazomethane addition involves initial C-C bond formation b to the ester.…”

“…These compounds also readily undergo Diels-Alder reactions with cyclopentadiene, to give a mixture of two diastereoisomers 469 , and with unsymmetrical butadienes 470,471 or with isoprene 472 . 2-Oxindolin-3-ylidene derivatives undergo cycloaddition with phenylnitrile oxide to yield the corresponding oxazoles 462 .…”