Construction of Contiguous Tetrasubstituted Carbon Stereocenters by Intramolecular Crossed Benzoin Reactions Catalyzed by N-Heterocyclic Carbene (NHC) Organocatalyst
Autor: | Ryoko Obayashi, Takashi Sakai, Kumiko Akihara, Tadashi Ema |
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Rok vydání: | 2012 |
Předmět: | |
Zdroj: | Advanced Synthesis & Catalysis. 354:3283-3290 |
ISSN: | 1615-4150 |
DOI: | 10.1002/adsc.201200499 |
Popis: | Bicyclic compounds with two contiguous tetrasubstituted carbon stereocenters at bridgehead positions were synthesized by N-heterocyclic carbene (NHC)-catalyzed intramolecular crossed benzoin reactions of symmetrical compounds. This desymmetrization strategy was applied to asymmetric synthesis with chiral NHC organocatalysts. Transition-state models were proposed to explain the enantioselectivity. A tricyclic compound with three contiguous tetrasubstituted carbon stereocenters was synthesized by a stepwise strategy. The molecular structure and absolute configuration of the (+)-enantiomer of this tricyclic compound were determined by X-ray crystallographic analysis. |
Databáze: | OpenAIRE |
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