100850-47-3Relevant academic research and scientific papers
Phosphine Catalyzed α-Arylation of Enones and Enals Using Hypervalent Bismuth Reagents: Regiospecific Enolate Arylation via Nucleophilic Catalysis
Koech, Phillip K.,Krische, Michael J.
, p. 5350 - 5351 (2004)
Exposure of enones and enals to 20 mol % tributylphosphine in the presence of triarylbismuth(V) dichlorides results in regiospecific aryl transfer to the α-position of the enone or enal pronucleophile. These results represent the first examples of enolate
Asymmetric Hydrogenation of Racemic 6-Aryl 1,4-Dioxaspiro[4.5]decan-7-ones to Functionalized Chiral ?a'Aryl Cyclohexanols via a Dynamic Kinetic Resolution
Yang, Dan,Yang, Ai-Jiao,Chen, Yong,Xie, Jian-Hua,Zhou, Qi-Lin
supporting information, p. 1616 - 1620 (2021/03/03)
A ruthenium-catalyzed asymmetric hydrogenation method for the synthesis of functionalized β-aryl cyclohexanols is described. With chiral spiro ruthenium catalyst (Ra,S,S)-5c, a series of racemic α-aryl cyclohexanones bearing a β-monoethylene ketal group were hydrogenated to the corresponding functionalized β-aryl cyclohexanols in high yields with enantioselectivity of up to 99% ee via a dynamic kinetic resolution. This protocol can be conducted on a decagram scale and provide potential approaches for the synthesis of optically active and densely functionalized aryl cyclohexanols.
Dynamic Kinetic Resolution of I-Substituted Cyclic β-Ketoesters via Asymmetric Hydrogenation: Constructing Chiral Cyclic β-Hydroxyesters with Three Contiguous Stereocenters
Yang, Dan,Wu, Xiong,Zheng, Xiao-Jie,Xie, Jian-Hua,Zhou, Qi-Lin
supporting information, p. 5153 - 5157 (2021/07/20)
An efficient asymmetric hydrogenation of racemic I-substituted cyclic β-ketoesters via dynamic kinetic resolution to provide chiral cyclic β-hydroxy esters with three contiguous stereocenters is reported. Using a chiral spiro iridium catalyst (R)-5 (Ir-SpiroSAP), a series of racemic I-Aryl/alkyl substituted cyclic β-ketoesters were hydrogenated to the corresponding chiral cyclic β-hydroxy esters in high yields (84-97%) with good to excellent enantioselectivities (69->99% ee) and cis,cis-selectivities (up to >99:1).
Synthesis of Functionalized Dihydrobenzofurans by Direct Aryl C?O Bond Formation under Mild Conditions
Alvarado, Joseph,Fournier, Jeremy,Zakarian, Armen
supporting information, p. 11625 - 11628 (2016/10/24)
A method for the synthesis of dihydrobenzofurans by a direct aryl C?O bond formation is described. A mechanistic pathway for the reaction, distinct from previously described similar transformations, allows for mild reaction conditions that are expected to be compatible with functionalized substrates.
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).
Use of conjugated dienones in cyclialkylations: Total syntheses of arucadiol, 1,2-didehydromiltirone, (±)-hinokione, (±)-nimbidiol, sageone, and miltirone
Majetich, George,Liu, Shuang,Fang, Jing,Siesel, David,Zhang, Yong
, p. 6928 - 6951 (2007/10/03)
Functionalized hydrophenanthrenes can be prepared using a cyclialkylation-based strategy. These annulations are highly dependent on the directing effects of the arene substitutents and on conformational considerations. The utility of this methodology was featured in the syntheses of six diterpenoids.
SYNTHESIS AND STRUCTURE OF 1,2,3,4,4a,10a-HEXAHYDROPHENANTHRENES SUBSTITUTED ON THE AROMATIC RING
Chini, Marco,Crotti, Paolo,Macchia, Franco,Domiano, Paolo
, p. 369 - 374 (2007/10/02)
6-Methoxy- (1b) and 7-bromo-trans-1,2,3,4,4a,10a-hexahydrophenanthrene (1c) have been prepared from their corresponding 9-oxo derivatives 4b and 4c.The 6-methoxy compound 4b has been prepared through a multi-step synthesis, including a cyclization reaction, starting from 2-(m-methoxyphenyl)-2-cyclohexenone, 8.The 7-bromo derivative 4c has been prepared as the only product by bromination of the known ketone 4a, unsubstituted on the aromatic ring, by means of the so called >.The structure and configuration of 1b has been established through X-ray crystal structure determination of the acetate of the hydrobromous acid adduct of 1b.The position of the bromine in all the 7-bromo derivatives has been established by means of an 1H NMR study of the aromatic pattern of the ketone 4c.
