Formation of Complex α-Imino Esters via Multihetero-Cope Rearrangement­ of α-Keto Ester Derived Nitrones

α-Amination of keto-nitrones via multihetero-Cope rearrangement employing an imidoyl chloride reagent.

α-Aminations of ketone-derived nitrones have been developed via [3,3]-rearrangement of the intermediates generated upon condensation with imidoyl chlorides. Careful reagent selection provides synthetically attractive amino protecting groups. The enediamide or α'-carbamoyl enamide products can be hydrolyzed to the desired carbonyl, or exposed to electrophiles for further α-functionalization.

Indium - mediated Allylation of α - Imino Esters in Aqueous Media

Synthesis of chiral N-phosphinyl α-imino esters and their application in asymmetric synthesis of α-amino esters by reduction

A variety of chiral N-phosphinyl α-imino esters have been synthesized for the first time from ketoesters and phosphinylamide, which were then reduced by L-selectride to give the corresponding N-phosphinyl-protected α-amino esters. The reduction proceeded very well with excellent chemical yields (88-98%) as well as high diastereoselectivities (96:4 to 99:1). Some of these products could be obtai...

Organocatalytic asymmetric Michael-type reaction between β,γ-unsaturated α-keto ester and α-nitro ketone.

A Michael-type reaction of β,γ-unsaturated α-keto ester and α-nitro ketone was established. With a thiourea catalyst derived from cinchona alkaloid, the reactions afford products in 47-94% yields with 68-96% ee.

Copper-catalyzed cascade reactions of α,β-unsaturated esters with keto esters

A copper-catalyzed cascade reaction of α,β-unsaturated esters with keto esters is reported. It features a copper-catalyzed reductive aldolization followed by a lactonization. This method provides a facile approach to prepare γ-carboxymethyl-γ-lactones and δ-carboxymethyl-δ-lactones under mild reaction conditions.