655243-58-6Relevant articles and documents
Divergent Synthesis of Oxa-Cyclic Nitrones through Gold(I)-Catalyzed 1,3-Azaprotio Transfer of Propargylic α-Ketocarboxylate Oximes: Experimental and DFT Studies
Wang, Chunhong,Cui, Qi,Zhang, Zhixin,Yao, Zhu-Jun,Wang, Shaozhong,Yu, Zhi-Xiang
supporting information, p. 9821 - 9826 (2019/07/10)
1,3-Azaprotio transfer of propargylic α-ketocarboxylate oximes, a new type of alkynyl oximes featuring an ester tether, has been explored by taking advantage of gold catalysis. The incorporation of an oxygen atom to the chain of alkynyl oximes led to the formation of two different oxa-cyclic nitrones. It was found that internal alkynyl oximes with an E-configuration deliver five-membered nitrones, whereas terminal alkynyl oximes with an E-configuration afford six-membered nitrones. DFT calculations on four possible pathways supported a stepwise formation of C?N and C?H bonds, in which a 1,3-acyloxy-migration competes with the 1,3-azaprotio-transfer, especially in the case of internal alkynyl oximes. The relative nucleophilic properties of oxygen in the carbonyl group and the nitrogen in the oxime, the electronic effects of alkynes, and the influence of the ring system have been investigated computationally.
α-Oximono-esters as precursors to heterocycles - generation of oxazinone N-oxides and cycloaddition to alkene dipolarophiles
Heaney, Frances,Fenlon, Julie,O'Mahony, Colm,McArdle, Patrick,Cunningham, Desmond
, p. 4302 - 4316 (2007/10/03)
Preparation of a series of terminally and internally substituted δ-alkenyl and δ-alkynyl esters 6,7 and 9, potential precursors to oxazin-2-one nitrones, has been attempted. Condensation between pyruvic or benzoylformic acid and the appropriate alcohol pr
