48115-38-4

A new series of Schiff bases derived from amino acids were developed as chiral ligands for Cu(II)-catalyzed asymmetric Henry reactions. The optimum ligand 7d exhibited outstanding catalytic efficiency in the Cu(II)-catalyzed asymmetric Henry additions of four nitroalkanes to different kinds of aldehydes to produce 76 desired adducts in high yields (up to 96%) with excellent enantioselectivities, up to 99% enantiomeric excess (ee).

The direct C-H amination of arenes is an important strategy to streamline the discovery and preparation of functional molecules. Herein, we report an operationally simple arene C-H amination reaction that, in contrast to most literature precedent, affords directly the synthetically versatile primary aniline products without relying on protecting group manipulations. Inexpensive Fe(II)-sulfate serves as a convenient catalyst for the transformation. The reaction tolerates a wide scope of arenes, including structurally complex drugs. Importantly, the arene substrates are used as limiting reagents in the transformation. This operationally simple transformation should considerably accelerate the discovery of medicines and functional molecules.

The kinetic resolution of racemic secondary alcohols is a fundamental method for obtaining enantiomerically enriched alcohols. Compared to esterification, which is a well-established method for this purpose, kinetic resolution through enantioselective intermolecular acetalization has not been reported to date despite the fact that the formation of acetals is widely adopted to protect hydroxy groups. By taking advantage of the thermodynamics of acetalization by the addition of alcohols to enol ethers, a highly efficient kinetic resolution of racemic amino alcohols was achieved for the first time and in a practical manner using a chiral phosphoric acid catalyst.

An anthracenyl-modified chiral bis(oxazoline) copper complex has been demonstrated to efficiently promote nitroaldol reactions between structurally varying aldehydes and nitromethane or nitroethane. The catalyst was recovered through formation of a charge transfer complex between the chiral ligand and trinitrofluorenone and its subsequent precipitation with pentane. The efficiency of this procedure was proved through several consecutive catalytic cycles that allowed the sturdy formation of the expected product with a high enantioselectivity. The catalyst′s stability was also put to the test in an original multi-substrate procedure. Following the same recovery concept, a new heterogeneous procedure was tested for which trinitrofluorenone was covalently linked to a silica support. Asymmetric heterogeneous catalysis was performed under these conditions as one of the few examples demonstrating the potential catalyst recycling in nitroaldol reactions through reversible, non-covalent interactions. Copyright

Disclosed is a kit for use in the production of a molecular probe for PET drug screening for the purpose of producing a compound containing a short-lived radionuclide for PET applications. Specifically disclosed is a kit comprising a compound represented

Process for preparing optically active β-amino alcohols represented by a general formula (2): Ra—C*H(OH)—C*H(Rb)—Rc wherein Ra and Rc are each independently hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl, Rb is one member select

Condensation of (-)-norephedrine with excess formaldehyde under mild conditions leads to formation of the 2:1 condensation product N,N'-methylenebis(4-methyl-5-phenyl)oxazolidine compared with the reaction with 1 mol of formaldehyde, which leads to 4-methyl-5-phenyloxazolidine. 1H and 13C NMR spectroscopy was used to monitor the stability of this compound and its decomposition products. The 2:1 condensation product is found to be stable in CDC13 but breaks down rapidly in CD3OD to yield a 50:50 mixture of 4-methyl-5-phenyloxazolidine and 3-hydroxymethyl-4-methyl-5-phenyloxazolidine. Upon addition of D2O to this equimolar mixture, the latter compound decomposes to norephedrine and formaldehyde, whereas the former compound is stable.

Sequential addition of iBu2AlH and RLi or RMgX to Schiff base esters derived from amino acids provides a simple route to β-amino alcohols. The reaction procedes without racemization, and with high threo selectivity. Several representative sphingosines are synthesized.

Ephedrine and related optically active β-aminoalcohols can be prepared by zinc borohydride reduction of aryl O-protected magnesium imines and aryl α-hydroxyimimes which in turn are readily available from optically active cyanohydrins.

A series of nitro alkanes were converted into the corresponding amines with retention of configuration by transfer hydrogenation using ammonium formate and palladium on carbon.

Optically active bases are prepared by reacting the racemic base with an optically active half amide of an unsaturated aliphatic dicarboxylic acid of the formula STR1 where R1, R2 and R3 are the same of different and are hydrogen, halogen, a hydroxy group, a methyl group or a methoxy group or two of R1, R2 and R3 together are a methylenedioxy group, R4 is hydrogen or a methyl group, R5, R6 and R7 independently are hydrogen or a C1 -C4 alkyl group and n is 0 or 1 and optionally splitting an optically homogeneous salt fraction into the corresponding optically active base and the added half amide.

This invention relates to phenoxyalkylamines having the formula: SPC1 Wherein R is a radical selected from the group consisting of hydrogen and hydroxy, R2 is a radical selected from the group consisting of hydrogen and methyl, A is a radical s