1540-29-0Relevant articles and documents
Synthesis of some disubstituted cyanoacetamides as potential anticonvulsants.
Schwartz 2nd.,Worrell,Delgado
, p. 80 - 86 (1967)
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Synthetic Scope of Br?nsted Acid-Catalyzed Reactions of Carbonyl Compounds and Ethyl Diazoacetate
Rahaman, Mizzanoor,Ali, M. Shahnawaz,Jahan, Khorshada,Hinz, Damon,Belayet, Jawad Bin,Majinski, Ryan,Hossain, M. Mahmun
, p. 6138 - 6147 (2021/05/06)
The comprehensive study of the reactions of carbonyl compounds and ethyl diazoacetate in the presence of a Br?nsted acid catalyst is described. In result, a broad range of 3-oxo-esters were synthesized from a variety of ketones and aliphatic aldehydes by 1,2-aryl/alkyl/hydride shift. Aryl-methyl ketones produced only aryl-migrated products, whereas other ketones yielded a mixture of products. For diaryl ketones, the identity of two inseparable migrated products was confirmed by two-dimensional NMR spectroscopy.
Rh(I)-bisphosphine-catalyzed asymmetric, intermolecular hydroheteroarylation of α-substituted acrylate derivatives
Filloux, Claire M.,Rovis, Tomislav
supporting information, p. 508 - 517 (2015/01/30)
Asymmetric hydroheteroarylation of alkenes represents a convenient entry to elaborated heterocyclic motifs. While chiral acids are known to mediate asymmetric addition of electron-rich heteroarenes to Michael acceptors, very few methods exploit transition metals to catalyze alkylation of heterocycles with olefins via a C-H activation, migratory insertion sequence. Herein, we describe the development of an asymmetric, intermolecular hydroheteroarylation reaction of α-substituted acrylates with benzoxazoles. The reaction provides 2-substitued benzoxazoles in moderate to excellent yields and good to excellent enantioselectivities. Notably, a series of mechanistic studies appears to contradict a pathway involving enantioselective protonation of a Rh(I)-enolate, despite the fact that such a mechanism is invoked almost unanimously in the related addition of aryl boronic acids to methacrylate derivatives. Evidence suggests instead that migratory insertion or beta-hydride elimination is enantiodetermining and that isomerization of a Rh(I)-enolate to a Rh(I)-heterobenzyl species insulates the resultant α-stereocenter from epimerization. A bulky ligand, CTH-(R)-Xylyl-P-Phos, is crucial for reactivity and enantioselectivity, as it likely discourages undesired ligation of benzoxazole substrates or intermediates to on- or off-cycle rhodium complexes and attenuates coordination-promoted product epimerization.
