16231-67-7Relevant articles and documents
Kinetic and thermodynamic control of axial chirality in biaryl-derived fused oxazolidine lactams exploiting a centre-axis relay of unit efficiency
Edwards, David J.,House, David,Sheldrake, Helen M.,Stone, Susan J.,Wallace, Timothy W.
, p. 2658 - 2669 (2007)
The condensation of a 2-substituted-2-aminoethanol with methyl 2′-formylbiphenyl-2-carboxylate produces only two of the four possible axially chiral 6,7-dihydrodibenz[c,e]oxazolo[3,2-a]azepin-9(4bH)-ones (fused oxazolidine lactams), with kinetically controlled diastereoisomer ratios of up to 96: 4. Within each lactam product the central chirality of the oxazolidine-fused benzylic position C(4b) is relayed to the biaryl axis with unit efficiency, the mis-matching of these stereogenic elements being prohibited due to strain, as predicted by molecular mechanics calculations. Diastereoisomeric lactam pairs can be equilibrated by heating with acid, and under these thermodynamic conditions reversed diastereoisomer ratios of up to 26: 74 are observed. The Royal Society of Chemistry.
Atroposelective Synthesis of Axially Chiral Biaryls by Palladium-Catalyzed Asymmetric C?H Olefination Enabled by a Transient Chiral Auxiliary
Yao, Qi-Jun,Zhang, Shuo,Zhan, Bei-Bei,Shi, Bing-Feng
supporting information, p. 6617 - 6621 (2017/05/29)
Atroposelective synthesis of axially chiral biaryls by palladium-catalyzed C?H olefination, using tert-leucine as an inexpensive, catalytic, and transient chiral auxiliary, has been realized. This strategy provides a highly efficient and straightforward access to a broad range of enantioenriched biaryls in good yields (up to 98 %) with excellent enantioselectivities (95 to >99 % ee). Kinetic resolution of trisubstituted biaryls bearing sterically more demanding substituents is also operative, thus furnishing the optically active olefinated products with excellent selectivity (95 to >99 % ee, s-factor up to 600).
A microwave-assisted diastereoselective multicomponent reaction to access dibenzo[ c, e ]azepinones: Synthesis and biological evaluation
Mehta, Vaibhav P.,Modha, Sachin G.,Ruijter, Eelco,Van Hecke, Kristof,Van Meervelt, Luc,Pannecouque, Christophe,Balzarini, Jan,Orru, Romano V. A.,Van Der Eycken, Erik
supporting information; experimental part, p. 2828 - 2839 (2011/06/26)
An unprecedented microwave-assisted multicomponent strategy has been elaborated for the fast, efficient, and diastereoselective generation of the dibenzo[c,e]azepinone scaffold. The generated compounds were evaluated for their bioactivity.
Studies towards the synthesis of the northern polyene of viridenomycin and synthesis of Z-double bond analogues
Knowles, Jonathan P.,O'Connor, Victoria E.,Whiting, Andrew
, p. 1876 - 1886 (2011/04/25)
Viridenomycin is a structurally challenging, potentially biologically valuable molecule which has yet to succumb to total synthesis. Its instability, perhaps particularly associated with the northern polyene may contribute to the difficulties of piecing this molecule together. The synthesis of northern polyene models, including potentially stabilised analogues incorporating benzene rings as Z-alkene replacements, have been prepared using an efficient series of cross-coupling reactions. The resulting polyenes and polyene surrogates have been converted into tetraene ester and amide models of the viridenomycin system. These analogues have sufficient stability compared with the unsubstituted northern polyene analogue to be viable for future developing a strategy for the construction of viridenomycin and analogues.
Biarylmethyl indolines, indoles and tetrahydroquinolines, useful as serine protease inhibitors
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Page 26, (2010/02/09)
The present invention provides compounds of Formula (I): or a stereoisomer or pharmaceutically acceptable salt or hydrate form thereof, wherein the variables A, B, L1, L2, X1, X2, X3, X4 an
Poly(ethylene glycol) supported liquid phase synthesis of biaryls
Blettner, Carsten G.,K?nig, Wilfried A.,Stenzel, Wolfgang,Schotten, Theo
, p. 295 - 297 (2007/10/03)
The liquid phase synthesis of biaiyls via Suzuki cross-coupling reaction on polyethylene glycol) supports (PEGs) is described. The reaction is exemplified by parallel coupling of polymer bound aryl halides with boronic acids. Four different PEGs were employed as soluble polymer supports for parallel synthesis. The generated libraries include both sterically hindered aryl halides (2b, 2d) and boronic acids. The reactions were run in the homogeneous phase and the synthetic sequences performed in parallel fashion. Quantitative conversion in the Suzuki couplings was verified by 1H-NMR analysis (3a-r). The polymer bound products were isolated in good to excellent (52% to 98%) yields by either simple precipitation of the soluble support or column filtration.
Abnormal Products from the Exhaustive Ozone Oxidation of Phenanthrene in HCl/Methanol
Neumeister, Joachim,Griesbaum, Karl
, p. 1640 - 1642 (2007/10/02)
Exhaustive ozone treatment of phenanthrene (6) in HCl/methanol afforded unsubstituted (10a) and chloro-substituted 6H-dibenzopyran-6-ones (10b - d) in addition to the expected dimethyl 2,2'-biphenyldicarboxylate (9c).
Ozonolysis of Symmetrically 1,2-Disubstituted Ethylenes in HCl/Methanol Solutions: Acid Catalyzed Reactions of Primary Cleavage Products
Griesbaum, Karl,Neumeister, Joachim
, p. 2697 - 2706 (2007/10/02)
The ozonolysis of olefins in 1 M anhydrous solutions of hydrogen chloride in methanol at /= 0 deg C was investigated.Upon warm-up of the ozonolysis products, the peroxidic primary fragmentation products were converted into non peroxidic end-products by HCl-catalyzed reactions.Cyclopentene (1a) and cyclohexene (1b), e.g., afforded mixtures of the corresponding α,ω-dialdehydebis(dimethyl acetals) (8), dimethyl α,ω-dicarboxylates (9), and methyl ω-aldehyde dimethyl acetal carboxylates (10).Norbornene (1c) gave a mixture of the correspondingly substituted 1,3-cyclopentane compounds (8c - 10c), phenanthrene (22) gave a mixture of methyl 2'-formyl-2-biphenylcarboxylate (24a), 2,2'-biphenyldicarbaldehyde (24b), and dimethyl 2,2'-biphenyldicarboxylate (24c).A reaction scheme was advanced for the rationalization of the types and the distribution of the products.It was partly substantiated by model reactions.
Stereochemistry of Metallocenes, XLVI. - Biphenyl(tricarbonylchromium) Complexes, V. - Optically Active Tricarbonylchromium Complexes of Diphenic Acid and its Derivatives - Enantiomeric Purity, Circular Dichroism and Absolute Configuration
Schloegl, Karl,Schoelm, Richard
, p. 1877 - 1888 (2007/10/02)
Optically active mono and bis(tricarbonylchromium) complexes of diphenic acid and its monomethyl ester (cf. 7 and 8) were prepared by resolution via their cinchonidinium salts with enantiomeric purities up to 8percent.Kinetic resolution of the corresponding aldehyde 12 via reduction with a chiral lithium aluminium hydride was more successful.In this case either (+)-12 and the alcohol (-)-10 or the lactone (-)-16 were obtained.The maximum rotations D20 (in acetone) were determined by application of a chiral shift reagent to (-)-10 being 516 deg, 832 deg and 1094 deg for 10, 12 and 16; the optical yield of the asymmetric reduction was 33percent.Because of the preferred configurations and conformations of the biscomplexes and after comparing the CD spectra with those of benchrotrenes of known absolute configuration the chirality (S)M-(R)A-(S)M is proposed for (-)-10 and related biphenyl complexes (-)-12 and (-)-16.
