L. Wartski

1-4 Addition of carbanions to α-β unsaturated carbonyl compounds in the presence of HMPA : first evidence of kinetic control.

Abstract 1-4 addition of some carbanionic species is enhanced if HMPA is added to the carbanion prior α-enones. Examples of 1-4 additions occuring under kinetic control are disclosed.

Substituent effects on 1–2 versus 1–4 addition of lithiated arylacetonitriles to 2-cyclohexenones in tetrahydrofuran

Abstract The reaction of organolithium derivates with α β unsaturated ketones gives, generally, allylic alcohols resulting from 1–2 addition (1). Recently, it has been shown that 1–4 addition products can be obtained in diethyl ether or in tetrahydrofuran (THF) either under kinetic control (2), mainly when the carbonyl group is sterically hindered (3,4), or under thermodynamic control when the lithiated reagent is substituted by electron delocalizing groups (5–16).

Addition conjuguee-alkylation: stereochimie de la reaction des lithiens d'arylacetonitriles sur les cyclenones suivie du piegeage par l'iodure de methyle en une seule operation

Abstract The stereochemistry of trapping of enolates, resulting from reaction of lithiated arylacetonitriles to cyclenones, by methyl iodide, is examined. In a medium such as THF-HMPT , the trans 2,3-disubstituted cyclanones are obtained with good yields, and moreover in nearly all cases alkylation takes place under kinetic control.

A Method of Conjugate Addition of Acetonitrile and Propionitrile to Cyclenones : Synthesis of 3 Cyanomethyl and Cyano-1' Ethylcyclanones

Abstract Conjugate addition on α-unsaturated carbonyl compounds is an important method for carbon-carbon bond making. This can be easily realized using lithiated stabilized carbanions such as [ArCHCN]-Li+ (1). However only carbonyl attack is observed using metallated acetonitriles [CH2CN]-M+ in THF whatever the cation (Li+, Na+, K+) is (1a).

Asymmetric synthesis of N-phenylethyl-2-phenyldecahydroquinolin-4-ones via Lewis acid catalyzed imino-Diels–Alder reaction

Abstract The asymmetric synthesis of N -phenylethyl-2-phenyldecahydroquinolin-4-ones was performed via a Lewis acid catalyzed imino-Diels–Alder reaction between the enantiopure ( R )- N -phenylethylbenzylideneimine and the trimethylsilyl enol ether of acetylcyclohexene. The regio- and stereoselective formation of intermediary bicyclic enoxysilanes, followed by their stereoselective protonation was evidenced. The initial stereoselectivity was kept only if the reaction mixture was treated using controlled basic conditions. Three enantiopure title compounds were isolated with a 5–15% yield.

Synthesis of γ-cyanoaldehydes: conjugated addition of lithiated anions of arylacetonitriles to αβ-unsaturated aldehydes and imines

γ-Cyanoaldehydes may be synthesized by the reaction of lithiated arylacetonitriles with either αβ-unsaturated aldehydes or αβ-unsaturated imines.