< 10alamenos9. Concurso de micro y nano-relatos

The Concept of Delayed Catalysis in Enantioselective Catalysts

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Abstract

Efficient synthesis of enantiomerically enriched amines often demands oxidation-state adjustments, protection/deprotection processes, and purification procedures that increase cost and waste, and limit applicability. When diastereomers can be formed, one isomer is attainable. In this Lecture we will discuss how nitriles, commonly viewed as insufficiently reactive, can be transformed directly to multifunctional unprotected homoallylic amines by enantioselective addition of a carbon-based nucleophile and diastereodivergent reduction of the resulting ketimine. Successful implementation requires that competing copper-based catalysts be present simultaneously, and that the slower-forming and less-reactive one engages first. This challenge was addressed by incorporation of a nonproductive side-cycle, fueled selectively by inexpensive additives, to delay the function of the more active catalyst.

 

 

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