Titanium-Catalyzed Stereoselective Synthesis of Spirooxindole Oxazolines
摘要:
A regio- and stereoselective cyclization between isatins and 5-methoxyoxazoles has been developed using catalytic titanium(IV) chloride (10 or 20 mol %) to afford spiro[3,3'-oxindoleoxazolines] in excellent yield (up to 99%) and diastereoselectivity (dr >99:1). Substitution at the 4-position of the oxazole controls nucleophilic attack to provide either the 2-oxazoline or 3-oxazoline spirocycle with excellent (>99:1) regiocontrol.
Titanium-Catalyzed Stereoselective Synthesis of Spirooxindole Oxazolines
作者:Joseph J. Badillo、Gary E. Arevalo、James C. Fettinger、Annaliese K. Franz
DOI:10.1021/ol1027305
日期:2011.2.4
A regio- and stereoselective cyclization between isatins and 5-methoxyoxazoles has been developed using catalytic titanium(IV) chloride (10 or 20 mol %) to afford spiro[3,3'-oxindoleoxazolines] in excellent yield (up to 99%) and diastereoselectivity (dr >99:1). Substitution at the 4-position of the oxazole controls nucleophilic attack to provide either the 2-oxazoline or 3-oxazoline spirocycle with excellent (>99:1) regiocontrol.
Catalytic Stereoselective Synthesis of Diverse Oxindoles and Spirooxindoles from Isatins
作者:Jacob P. MacDonald、Joseph J. Badillo、Gary E. Arevalo、Abel Silva-García、Annaliese K. Franz
DOI:10.1021/co300003c
日期:2012.4.9
two-step synthesis of triazole derivatives of oxindoles and spirooxindoles is presented. Using a common set of N-propargylated isatins, a series of mechanistically distinct stereoselective reactions with different combinations of nucleophiles and catalysts provide access to diverse hydroxy-oxindoles, spiroindolones, and spirocyclic oxazoline structures. The resulting N-propargylated oxindoles are then