Diethylzinc-Mediated One-Step Stereoselective Synthesis of α-Fluoroacrylates from Aldehydes and Ketones. Two Different Pathways Depending on the Carbonyl Partner
A efficient methodology allowing the one-pot stereoselective synthesis of alpha-fluoroacrylates, based on the addition of ethyl dibromofluoroacetate to a carbonyl derivative using diethylzinc as organometallic mediator, is described. Two different pathways have been identified depending on the involved carbonyl partner. In the case of aldehydes, an E2-type mechanism has been identified, whereas ketones go through an E1cb-type mechanism.
Elkik, Elias; Francesch, Charlette, Bulletin de la Societe Chimique de France, 1986, # 3, p. 423 - 428
作者:Elkik, Elias、Francesch, Charlette
DOI:——
日期:——
Pd- and Cu-Catalyzed Stereo- and Regiocontrolled Decarboxylative/CH Fluoroalkenylation of Heteroarenes
Pd/Cu‐catalyzed decarboxylative/directCH alkenylations of heteroarenes with α‐fluoroacrylic acid is reported. This method offers step‐economical and stereocontrolled access to valuable heteroarylated monofluoroalkenes as both Z and E isomers, which are known to be useful in the synthesis of fluorinated biomolecules.
An exceptionally stereoselective and general synthesis of (Z)-α-haloacrylates, ready to undergo various synthetic transformations, has been demonstrated from α-haloacetates and aldehydes in a one-pot manner via the titanium-enolate based asymmetric aldol condensation. Besides being an expedient synthetic procedure, the ready availability of diverse α-haloacetates, exceptional stereoselectivity, and high yields make the process a versatile transformation in organic synthesis. The potential of this method in up-scaling operations has been illustrated.