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Titanium(IV)-catalyzed stereoselective synthesis of spirooxindole-1-pyrrolines.

ABSTRACT: A stereoselective cyclization between alkylidene oxindoles and 5-methoxyoxazoles has been developed using catalytic titanium(IV) chloride (as low as 5 mol %) to afford spiro[3,3'-oxindole-1-pyrrolines] in excellent yield (up to 99%) and diastereoselectivity (up to 99:1). Using a chiral scandium(III)-indapybox/BArF complex affords enantioenriched spirooxindole-1-pyrrolines where a ligand-induced reversal of diastereoselectivity is observed. This methodology is further demonstrated for the synthesis of pyrrolines from malonate alkylidene and coumarin derivatives.

SUBMITTER: Badillo JJ

PROVIDER: S-EPMC4275133 | biostudies-other | 2014 Dec

REPOSITORIES: biostudies-other

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Titanium(IV)-catalyzed stereoselective synthesis of spirooxindole-1-pyrrolines.

Badillo Joseph J JJ Ribeiro Carlos J A CJ Olmstead Marilyn M MM Franz Annaliese K AK

Organic letters 20141204 24

A stereoselective cyclization between alkylidene oxindoles and 5-methoxyoxazoles has been developed using catalytic titanium(IV) chloride (as low as 5 mol %) to afford spiro[3,3'-oxindole-1-pyrrolines] in excellent yield (up to 99%) and diastereoselectivity (up to 99:1). Using a chiral scandium(III)-indapybox/BArF complex affords enantioenriched spirooxindole-1-pyrrolines where a ligand-induced reversal of diastereoselectivity is observed. This methodology is further demonstrated for the synthes ...[more]

PMID: 25474118

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