61203-83-6Relevant articles and documents
Construction of Distant Stereocenters by Enantioselective Desymmetrizing Carbonyl-Ene Reaction
Luo, Weiwei,Lin, Lili,Zhang, Yu,Liu, Xiaohua,Feng, Xiaoming
, p. 3374 - 3377 (2017/07/15)
An efficient desymmetrizing carbonyl-ene reaction of 1-substituted 4-methylenecyclohexanes with glyoxal derivatives was thus executed by a chiral N,N′-dioxide/NiII catalyst, providing facile access to cyclohexene derivatives bearing two remote 1,6-related stereocenters. This distal stereocontrol methodology originates from the efficient interaction between the catalyst with enophiles, discrimination of the two chair conformations of olefinic components, and the intrinsic six-membered transition-state structure of ene process.
A base-promoted deprotection of 1,3-dioxolanes to ketones
Yuan, Changchun,Yang, Li,Yue, Guizhou,Yu, Tianzi,Zhong, Weiming,Liu, Bo
supporting information, p. 6972 - 6976 (2013/01/15)
An effective deprotection methodology of dioxolanes was developed, affording moderate to excellent yield via a LTMP-promoted reaction in THF, which displays admirable chemoselectivity in the presence of dimethylketal, 1,3-dioxane, 1,3-dithiane, or other acid-sensitive protective groups.
Nitrosobenzene-mediated C-C bond cleavage reactions and spectral observation of an oxazetidin-4-one ring system
Payette, Joshua N.,Yamamoto, Hisashi
supporting information; experimental part, p. 12276 - 12278 (2009/02/05)
While bond formation processes have traditionally garnered the attention of the chemical community, methods facilitating bond breaking remain relatively undeveloped. We report a novel, transition-metal-free oxidative C-C bond cleavage process for a broad range of ester and dicarbonyl compounds involving carbanion addition to nitrosobenzene. ReactIR experiments on the nitrosobenzene-mediated oxidative decarboxylation of esters indicate the reaction proceeds via fragmentation of a previously unobserved oxazetidin-4-one heterocycle, characterized by an intense IR stretching frequency at 1846 cm-1. These mechanistic studies have allowed further expansion of this protocol to ketone cleavage reactions of a diverse array of β-ketoester and 1,3-diketone substrates. The conceptual and mechanistic insights offered by this study are likely to provide a platform for further development of bond-breaking methodologies. Copyright
Amidino derivatives useful as nitric oxide synthase inhibitors
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, (2008/06/13)
The current invention discloses useful pharmaceutical compositions containing amidino derivative useful as nitric oxide synthase inhibitors.
Amidino dervatives useful as nitric oxide synthase inhibitors
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, (2008/06/13)
The current invention discloses useful pharmaceutical compositions containing azepine derivatives useful as nitric oxide synthase inhibitors.
The Synthesis and Liquid Crystal Behavior of p-Benzotrifluoride Compounds I
Liang, Jason C.,Kumar, Satyendra
, p. 77 - 84 (2007/10/02)
Three compounds with the R-X-Y-CF3 structure were synthesized where X is a trans cyclohexil ring.Y is a benzene ring and R is an alkyl group.The structure assignments were confirmed by carbon 13NMR and the compounds were purified by preparative liquid chromatography.The separation of cis and trans isomers of 1-p-trifluorophenyl-4-alkyl-cyclohexanol is also discussed.Although these compounds do not have a liquid crystalline phase themselves, a liquid crystal mixture containing them shows a much faster turn off speed than materials without them.Keywords: benzotrifluoride, trifluoromethyl, time response, TN cell
Aliphatic Liquid Crystals, 2. Some Nematic Derivatives of all-trans-Perhydrophenanthrene
Sucrow, Wolfgang,Minas, Hermann,Stegemeyer, Horst,Geschwinder, Peter,Murawski, Hans-Ruediger,Krueger, Carl
, p. 3332 - 3349 (2007/10/02)
A stereoselective synthesis of the all-trans-7-alkylperhydro-2-phenanthrenols 15a-f in 11 steps and 28 liquid crystalline esters 16 of 15a-f are described, additionally some further derivatives of 7-alkylperhydro-2-phenanthrenol.An X-ray structure analysis of ester 16ec is reported.
A New Class of Chiral Smectic Liquid Crystals: Substituted Biphenylylcyclohexylideneethanones Having an Axial Chirality
Solladie, Guy,Zimmermann, Richard
, p. 4062 - 4068 (2007/10/02)
The introduction of chiral cyclohexylideneethanone unit in a potential mesomorphic structure leads to the first family of optically active liquid crystals having an axial chirality.Racemic compounds 2 were synthesized by a Wittig-type coupling between β-keto phosphonates 6 (R1 = n-C5H11) and substituted cyclohexanone 7 (R2 = H, CH3, t-Bu, OCH3, O-n-C5H11, CO2Et, OCOC6H4CN, OCOC6H4Cl).The optically active molecules 12 were prepared by a new route using the asymmetric coupling of a carbanion α to a chiral sulfoxide 9 (R2 = n-C5H11, CH2OEt) and a substituted biphenyl acid chloride (Ar = R'C6H4C6H4 with R' = n-C5H11, CH3O, n-C8H17O, CN) followed by a stereospecific pyrolytic elimination of the sulfoxide moiety.Derivatives containing only one aromatic ring were not mesomorphic in contrast to those having a biphenyl system.
