Investigation of Grignard Reagent as an Advanced Base for Aza-Claisen Rearrangement

Microwave accelerated aza-Claisen rearrangement.

A study of microwave-induced and standard thermal Overman rearrangement of selected allylic trichloroacetimidates 1a-1f, 6-8 to the corresponding acetamides 2a-2f, 9-11 is reported. The microwave-assisted rearrangement of trifluoroacetimidate 13 is also described. Using this methodology, an efficient access to versatile allylic trihaloacetamides building synthons was established.

Synthesis of polyfluoroalkyl cyclobutenes from 3-aza-1,5-enynes via an aza-Claisen rearrangement/cyclization cascade.

A facile synthetic route to access polyfluoroalkyl functionalized cyclobutenes bearing an exo cyclic double bond from 3-aza-1,5-enynes is reported. The reaction proceeds via a thermal aza-Claisen rearrangement to give an allene-imine intermediate; subsequent cyclization affords the cyclobutene core. The kinetics of the transformation of starting material and the intermediate was studied by (1)H...

A stereo-controlled access to functionalized macrolactams via an aza-Claisen rearrangement.

A novel and stereo-controlled method for the preparation of functionalized macrolactams was developed. The process involves stereoselective enol ether formation, followed by an azacyclic ring expansion via an aza-Claisen rearrangement. Herewith, we describe a systematic investigation of an aza-Claisen rearrangement-induced ring expansion of azacycles prepared by appending E/Z-enol ethers to the...

Stereoselective α-fluoroamide and α-fluoro-γ-lactone synthesis by an asymmetric zwitterionic aza-Claisen rearrangement

BACKGROUND Asymmetric introduction of fluorine alpha-to a carbonyl has become popular recently, largely because the direct fluorination of enolates by asymmetric electrophilic fluorinating reagents has improved, and as a result such compounds are becoming attractive synthons. We have sought an alternative but straightforward asymmetric method to this class of compounds, utilising the zwitterion...

The Claisen Rearrangement