Enantioselective Aziridination of Cyclic Enals Facilitated by the Fluorine-Iminium Ion<i>Gauche</i>Effect
作者:István Gábor Molnár、Eva-Maria Tanzer、Constantin Daniliuc、Ryan Gilmour
DOI:10.1002/chem.201303586
日期:2014.1.13
of an enantioinduction strategy. Treatment of this intermediate with a “nitrene” source furnished a series of novel, opticallyactive aziridines (e.r. up to 99.5:0.5). Further derivatisation of the product aziridines gives facile access to various amino acid derivatives, including β‐fluoroamino acids. Crystallographic analyses of both the aziridines and their derivatives are disclosed.
Organocatalyzed Aziridination of α-Branched Enals: Enantioselective Synthesis of Aziridines with a Quaternary Stereocenter
作者:Alaric Desmarchelier、Danilo Pereira de Sant'Ana、Vincent Terrasson、Jean Marc Campagne、Xavier Moreau、Christine Greck、Renata Marcia de Figueiredo
DOI:10.1002/ejoc.201100437
日期:2011.7
α-substituted-α,β-unsaturated aldehydes is described. The products were obtained in good yields (up to 86 %) and enantioselectivities (up to 90 % ee) and could rapidly be transformed under various conditions, including ring opening, to afford useful small molecules possessing not only the aziridine and aldehyde moieties but also other functionalities such as alcohol, acid, ester, or amino alcohol.
The first example of a highly enantioselective organocatalytic aziridination of α-substitutedα,β-unsaturatedaldehydes is presented. The reaction is catalyzed by simple chiral amines and gives access to highly functional terminal azirdines containing an α-tertiary amine stereocenter in high yields and enantiomeric ratios (95.5:4.5–98:2).