Electrophilic cyclization of unsaturated amides

Preparation of Imino Lactones by Electrophilic Cyclization of β,γ‐Unsaturated Hydroxamates: Formation of 3‐Cyanoprop‐2‐en‐1‐ones through Fragmentation Reactions

“…We first examined the reactivities of the hydroxamic acid 3 and the hydroxamates 4, 5a and 5b, obtained from 3-cyclohexylidenepropanoic acid (1). [7] These compounds were prepared as reported in Scheme 1.…”

“…0.148 g (68 %). 1 N-(Acetoxy)-3-cyclohexylidenepropanamide (4): Pyridine (1.06 equiv., 30 µL) was added over 10 min to a THF solution (10 mL) of hydroxamic acid 2 (66 mg, 0.39 mmol), cooled to 0°C. The solution was stirred for 20 min at room temp., and acetyl chloride (1.06 equiv., 40 µL) was added dropwise.…”

“…[1] Our research into the reactivity of bis(collidine)bromine(I) hexafluorophosphate [2] led us to examine the case of unsaturated hydroxamates. Their reaction behaviour with electrophiles has been briefly reported on in the literature.…”

Current Methods for Asymmetric Halogenation of Olefins

“…Electrophile-promoted cyclizations of functionalized w-substituted carboxylic acids [4] (and amides [5] ) are useful methods for the construction of lactones or other heterocyclic compounds. [6] The most popular variants of these reactions involve halogens, with iodocyclizations playing a particularly important role in total synthesis.…”

Microwave assisted green synthesis of aryl methoxylated benzamides and 2-oxazolines from biomass

“…In organic synthesis, 2-oxazoline has demonstrated a vast synthetic potential as the protected form of hydroxyamino acids and amino alcohols, remarkably efficient director for O-lithiation of benzene ring and nucleophilic aromatic substitution [4][5][6]. Additionally, chiral oxazolines represent versatile building blocks for the synthesis of polyfunctionalized compounds, and are widely used as chiral ligands or chiral auxiliaries for regio-and stereochemical control in asymmetric synthesis [ 10 , 11 ].…”