title: Stereoselective synthesis of spirooxindole derivatives using an organocatalyzed tandem Michael-Michael reaction.
abstract: A highly efficient stereoselective method for the synthesis of functionalized spirooxindole derivatives with three stereogenic centers was realized through an organocatalytic tandem Michael-Michael reaction. By employing (S)-α,α-diphenylprolinol trimethylsilyl ether as the catalyst and N,N'-bis[3,5-bis(trifluoromethyl)phenyl]thiourea as the cocatalyst, the reaction between N-tritylisatylidenemalononitriles and (E)-7-alkyl-7-oxohept-5-enals yields the desired spirooxindole products in good yields (76-95%) and with excellent diastereoselectivities (up to 97 : 3 dr) and enantioselectivities (up to 98% ee), which can be stereoselectively converted into the spiro[indoline-3,8'-isoquinoline] derivative through an intramolecular reductive amination reaction.
authors.affiliation: Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249-0698, USA. cong.zhao@utsa.edu.
authors.forename: Huicai
authors.initials: H
authors.lastname: Huang
authors.affiliation: Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249-0698, USA. cong.zhao@utsa.edu.
authors.forename: Manisha
authors.initials: M
authors.lastname: Bihani
authors.affiliation: Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249-0698, USA. cong.zhao@utsa.edu.
authors.forename: John C-G
authors.initials: JC
authors.lastname: Zhao