Alkylation of Enolate IonsThomas A Newton
Asymmetric induction in the alkylation of enolate anion with the optically active selenonium ionsindan derivativesMethyl phenyl selenide (I) is ethylated to form the racemic selenonium salt (IIIa) which is optically resolved via the D-camphor sulfonates.doi:10.1002/chin.198727142...
One of the fundamental processes for carbon-carbon bond formation is a reaction between a nucleophilic carbon and an electrophilic one. The focus in this chapter is on enolate ions, imine anions, and enamines, which are the most useful kinds of carbon nucleophiles, and on their reactions with...
Before the ability to control enolate anion reactions by using kinetic or thermodynamic reactions conditions was available, regioselectivity in the aldol condensation or enolate alkylation was an important problem. A method was developed that is effective in controlling the kinetic-thermodynamic product. In...
The more loosely coordinated sodium or potassium cations are preferable to the strongly coordinating lithium and magnesium ions. The preferred conditions for N-alkylation of pyrroles involve formation of the anion in liquid ammonia or DMSO. Appropriate bases are, respectively, sodium amide generated in...
The direct quench of the reaction with benzyl bromide afforded the further α-alkylation product 6a in a good yield of 79% (Fig. 4a), demonstrating the enolate intermediate. Fig. 4: Control Experiments. a Capture of the enolate intermediate. b Parallel competitive reaction. c Intramolecular ...
CAS past decade?5 Hence, the ability to facilitate the highly diastereo— o2bof9yn and enantioselective propargylic alkylation of unstabilized ketone morpholinium ions prevents the shift of the H—atom to CB of the enolates or their equivalents with propargylic esters to directly and selectively ...
Su Chen1 & Xin-Yuan Liu1 Although great success has been achieved in asymmetric fluoroalkylation reactions via nucleophilic or electrophilic processes, the development of asymmetric radical versions of this type of reactions remains a formidable challenge because of the involvement of highly reactive rad...
allylic alkylation of a nonstabilized ke- tone enolate was reported by Trost and Schroeder. [6a] Thus, the tin enolate 7b, generated from 2-methyl tetralone (6), was submitted to a palladium-catalyzed allylation that was mediated by the C 2 - symmetric ligand 8 (Scheme 3). There- by,...
The most direct method involves the treatment of an enolate derived from an ester or ketone with a suitable sulphenylating agent. While sulphenyl halides or other derivatives suffice, disulphides are more convenient. Thus, ester or lactone enolates react with dimethyl disulphide or diphenyl dis...