Asymmetric Organocatalytic Synthesis of Fluorinated β-Hydroxy Diazenes

Description

The nucleophilic addition of formaldehyde tert-butyl hydrazone to fluoromethyl ketones provides a valuable tool for the synthesis of highly functionalized β-hydroxy β-tri- and difluoromethyl diazenes. Excellent reactivities and moderate to good enantioselectivities (up to 90 % ee) were achieved by H-bonding activation exerted by tert-Leucine derived H-bonding (squaramide or thiourea) organocatalysts. Subsequent derivatizations in one-pot fashion provide synthetically useful intermediates for target-oriented synthesis: tri- and di-fluoromethylated azoxy compounds, β-amino alcohols, α-hydroxy aldoximes and derivatives thereof.

Abstract

Ministerio de Economía y Competitividad CTQ2016-76908-C2-1-P, CTQ2016-76908-C2-2-P

Abstract

Junta de Andalucía 2012/FQM1078

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