Abstract
Phosphine-catalyzed enantioselective annulation reactions involving ketimines are a daunting synthetic challenge owing to the intrinsic low reactivity of ketimine substrates. A highly enantioselective [3+2] cycloaddition reaction that makes use of isatin-derived ketimines as reaction partners was developed. Notably, both simple and γ-substituted allenoates could be utilized, and various 3,2′-pyrrolidinyl spirooxindoles with a tetrasubstituted stereocenter were obtained in excellent yields and with nearly perfect enantioselectivity (>98 % ee in all cases). Like a circle in a spiral: A highly enantioselective [3+2] cycloaddition reaction that makes use of isatin-derived ketimines as reaction partners has been developed. Both simple and γ-substituted allenoates could be utilized, and various 3,2′-pyrrolidinyl spirooxindoles with a tetrasubstituted stereocenter were obtained in excellent yields and with nearly perfect enantioselectivity (>98 % ee in all cases).
Original language | English |
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Pages (from-to) | 6492-6496 |
Number of pages | 5 |
Journal | Angewandte Chemie - International Edition |
Volume | 55 |
Issue number | 22 |
DOIs | |
Publication status | Published - 23 May 2016 |
Externally published | Yes |
Keywords
- acyclic ketimines
- amino acids
- phosphine catalysts
- spirooxindoles
- [3+2] cycloaddition
ASJC Scopus subject areas
- Catalysis
- General Chemistry