5775-17-7Relevant academic research and scientific papers
A Method for the Catalytic Enantioselective Synthesis of Chiral α-Azido and α-Amino Ketones from Racemic α-Bromo Ketones, and Its Generalization to the Formation of Bonds to C, O, and S
Da Silva Gomes, Roberto,Corey
supporting information, p. 20058 - 20061 (2019/12/27)
A new and practical method has been developed for the transformation of racemic α-bromo ketones to chiral α-azido and α-amino ketones with high enantioselectivity using phase transfer, ion-pair mediated reactions with a recoverable chiral quaternary salt (10 mol %) as catalyst in fluorobenzene-water. The process has been generalized to a variety of other attachments including of C, O, S, and NHR.
Iron(iii) chloride hexahydrate-promoted selective hydroxylation and chlorination of benzyl ketone derivatives for the construction of hetero-quaternary scaffolds
Chen, Tao,Peng, Rui,Hu, Wenxin,Zhang, Fu-Min
supporting information, p. 9859 - 9867 (2016/10/31)
A novel and tunable α-hydroxylation/α-chlorination of benzyl ketone derivatives has been developed for the construction of hetero-quaternary carbon centers by iron(iii) chloride hexahydrate mediated selective transformations through the application of dif
Mimicking the reaction of phenylalanine ammonia lyase by a synthetic model
Rettig, Martin,Sigrist, Andreas,Retey, Janos
, p. 2246 - 2265 (2007/10/03)
Phenylalanine and histidine ammonia lyases (PAL and HAL) catalyze the reversible conversion of α-amino acids to the corresponding acrylic acids by elimination of ammonia. The prosthetic group 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO) at the active site of both enzymes supposedly undergoes an electrophilic attack at the aromatic nucleus in the first step of the mechanism of action. Since no chemical analogy existed for such an electrophile-assisted elimination, we synthesized model compounds, some portion of which mimicked the essentials of the substrate phenylalanine and another portion the electrophilic Michael acceptor in a sterically appropriate distance. The first model, (±)-rel-(1R,2S,3S)-3-[1-methylidene-2-oxo-2-(pyrrolidin-1-yl)ethyl]-2-phenyl cyclohexanamine (7) did not react under Friedel-Crafts conditions in the expected way (Scheme 2). The second model compound (±)-2-rel-(1R,2S,3S)-3-(dimethylamino)-2-(3-methoxyphenyl)cyclohexyl]prop-2- enal (12) with a more nucleophilic methoxyphenyl and a more electrophilic α,β-unsaturated carbonyl moiety, underwent an intramolecular Friedel-Crafts-type substitution, but no elimination of the dimethylamino group (Scheme 4). The third model compound, (±)-γ-[(dimethylamino)methyl]-3-methoxy-2,4,6-trimethyl-α-methylidenebenze nebutanal (25) eliminated dimethylamine upon treatment with Lewis acids and subsequent hydrolysis of the intermediate (Scheme 6). When the 3-methoxy-2,4,6-trimethylphenyl moiety of 25 was replaced by the 2,4,6-trimethyl-3-nitrophenyl group, no elimination product could be observed (Scheme 7).
Enantioselective protonation of samarium enolates derived from α- heterosubstituted ketones and lactone by SmI2-mediated reduction
Nakamura, Yutaka,Takeuchi, Seiji,Ohgo, Yoshiaki,Yamaoka, Makoto,Yoshida, Akihiro,Mikami, Koichi
, p. 4595 - 4620 (2007/10/03)
SmI2-mediated reductive cleavage of α-heterosubstituents of α-alkyl or α-aryl ketones and lactone gave the corresponding 'thermodynamic samarium enolates'. Enantioselective protonation of the samarium enolates with C2- symmetric chiral diols afforded the corresponding ketones and lactone in moderate to high enantioselectivities.
