13435-12-6Relevant articles and documents
Development of a new class of chiral phosphorus ligands: P-chirogenic diaminophosphine oxides. A unique source of enantioselection in Pd-catalyzed asymmetric construction of quaternary carbons
Nemoto, Tetsuhiro,Masuda, Takamasa,Matsumoto, Takayoshi,Hamada, Yasumasa
, p. 7172 - 7178 (2007/10/03)
We have recently developed a new class of chiral phosphorus ligands: P-chirogenic diaminophosphine oxides. These pentavalent phosphorus compounds have been successfully applied to Pd-catalyzed asymmetric construction of tertiary and quaternary carbons. The actual ligand structure was the trivalent phosphorus species 17, which was generated in situ by BSA-induced P(V) to P(III) transformation of 6, the preligand. Detailed mechanistic studies, including asymmetric amplification and initial rate kinetics, revealed that complex 18 [Pd-17 (1:2) complex] was the active catalyst. The important function of the nitrogen atom on the sidearm in the ligands was also clarified. The source of enantioselection in the construction of asymmetric quaternary carbons was the secondary ligand substrate interaction mediated by N-Zn coordination.
&α-L-ribo-Configured Locked Nucleic Acid (&α-L-LNA): Synthesis and Properties
Soerensen, Mads D.,Kvaernoe, Lisbet,Bryld, Torsten,Hakansson, Anders E.,Verbeure, Birgit,Gaubert, Gilles,Herdewijn, Piet,Wengel, Jesper
, p. 2164 - 2176 (2007/10/03)
The syntheses of monomeric nucleosides and 3'-O-phosphoramidite building blocks en route to α-L-ribo-configured locked nucleic acids (α-L-LNA), composed entirely of α-L-LNA monomers (α-L-ribo configuration) or of a mixture of α-L-LNA and DNA monomers (β-D
Catalyst for use in production of epoxide, method for producing the catalyst, and method for producing epoxide
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, (2008/06/13)
To provide an epoxide-production-use catalyst that is suitably used for producing an epoxide by partial oxidation of an unsaturated hydrocarbon, a catalyst in accordance with the present invention is obtained by fixing gold fine particles to a carrier containing an oxide containing at least one of titanium and zirconium, and has an acid quantity of not more than 0.1 mmol/g determined by the NH3-TPD method. Such a catalyst for epoxide producing use can be produced by, for instance, fixing gold fine particles to a carrier having an acid quantity of not more than 0.15 mmol/g. The catalyst for epoxide producing use arranged as above is preferably used as a catalyst in partial oxidation of an unsaturated hydrocarbon to produce a corresponding epoxide.
Synthesis of phosphino oxazoline ligand libraries from amino acid and phosphino carboxylate building blocks
Gilbertson, Scott R.,Chang, Cheng-Wei T.
, p. 8424 - 8431 (2007/10/03)
A modular route to new phosphine-oxazoline ligands is reported. The ability of these ligands to asymmetrically catalyze the addition of dimethyl malonate to 1,3-diphenylprop-2-enyl acetate was investigated. The best of these ligands gave a palladium complex which catalyzed the addition of dimethyl malonate to 1,3-diphenylprop-2-enyl acetate in a 99% yield and in 98% enantiomeric excess (Table 3, entry 11).
Carbacephalosporin compound, their preparation and use
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, (2008/06/13)
Carbacephalosporin compounds of formula (I), STR1 salts thereof, processes for their synthesis and uses thereof, wherein: R1 is hydrogen, methoxy or formamido; R2 is an acyl group; CO2 R3 is a carboxy group or a carboxylate anion, or R3 is a carboxy protecting group or a pharmaceutically acceptable salt-forming group or in vivo hydrolysable ester group; R4, R5, R6 and R7 represent hydrogen or a substituent; R4 and R7 may be replaced by a chemical bond between the two carbon atoms shown; R5 and R6 may be linked together into a cyclic system. The compounds (I) have antibacterial properties.
SUR L'OBTENTION HAUTEMENT REGIO- ET STEREOSELECTIVED'ENOXYSILANES PAR ACTION DU BIS(TRIMETHYLSILYL)ACETAMIDE EN MILIEU HMPT SUR LESS DERIVES CARBONYLES ENOLISABLES
Dedier, James,Gerval, Pierre,Frainnet, Emile
, p. 183 - 198 (2007/10/02)
The authors describe a new and general method for the preparation of enoxysilanes by silylation of enolizable aldehydes and ketones by use of bis(trimethylsilyl)acetamide in HMPT, in the presence of very small quantities of sodium metal(or another basic a
