35005-72-2Relevant academic research and scientific papers
Nitrile oxide versus nitrone - Switching regioselectivity of intramolecular 1,3-dipolar cycloadditions towards the preparation of aminopiperidinecarboxylates
Wuerdemann, Martina,Christoffers, Jens
, p. 7421 - 7431 (2013/11/19)
3-(Allylamino)- and 3-(propargylamino)propanal were converted via the corresponding oximes into nitrile oxides, which readily underwent intramolecular 1,3-dipolar cycloadditions to furnish a piperidine-annulated isoxazole or isoxazoline. The annulated isoxazoline was transformed into orthogonally carbamate-protected cis- and trans-4-aminopiperidine-3-carboxylates, both representing interesting scaffolds for combinatorial chemistry. Through sequences of amidations and deprotections two triply functionalized products were obtained as examples for diversification. After Boc removal, the piperidino-annulated isoxazole was also subjected to diversifying reactions, such as reductive amination, amidation, and the formation of sulfonamido- and ureido-substituted derivatives. Intramolecular 1,3-dipolar cycloaddition of nitrile oxides is the key for the formation of aminopiperidines from acrolein and allylamines. Copyright
