A phosphine‐free iridium‐catalyzed reaction of isoxazol‐5(4H)‐ones (isoxazolones) has been developed, and affords 2H‐azirines through decarboxylation and ring contraction. This method provides an efficient and environmentally benign protocol which could replace the conventional approaches used to synthesize 2H‐azirines.
Sigmatropic rearrangements in the allyl substituted oxazolinone system
作者:Albert Padwa、Mitsuo Akiba、Leslie A. Cohen、J.Gavin MacDonald
DOI:10.1016/s0040-4039(01)92926-0
日期:1981.1
Thermolysis and photolysis of several allyl substituted oxazolin-5-ones results in a sigmatropicrearrangement in accord with orbital symmetry predictions.
几个烯丙基取代的恶唑啉-5-酮的热解和光解导致与轨道对称性预测相符的σ重排。
Palladium-Catalyzed Selective Formation of Substituted Pyrroles from Alkene-tethered Cyclic Oxime Esters
Isoxazol-5(4H)-ones were used as nitrene precursors for the selective formation of trisubstituted pyrroles by applying a palladium-catalyzed decarboxylative ring-reconstruction method. The use of bulky biaryl-type monophosphine ligands was effective for improving the selectivity. Deuterium-labeling experiments suggested a mechanism involving beta-hydride elimination followed by reductive elimination from an aza-pi-allyl intermediate.
Aza Cope rearrangements in the cyclopropenyl- and allyl-substituted .DELTA.2-oxazolinone systems
作者:Albert Padwa、Mitsuo Akiba、Leslie A. Cohen、J. Gavin MacDonald
DOI:10.1021/jo00153a015
日期:1983.3
Photochemical transformations of small ring heterocycles. 81. Carbenic reactions of nitrile ylides. An example of a stepwise 1,3-dipolar cycloaddition