An asymmetric decarboxylative Csp(3)-Csp(2) cross-coupling has been achieved via the synergistic merger of photoredox and nickel catalysis. This mild, operationally simple protocol transforms a wide variety of naturally abundant α-amino acids and readily available aryl halides into valuable chiral benzylic amines in high enantiomeric excess, thereby producing motifs found in pharmacologically a...

In contrast to the photosensitization with a non-methylated analogue, supramolecular photochirogenesis with a novel permethylated mono(6-O-benzoyl)-beta-cyclodextrin exhibited a critical dependence of the product's enantiomeric excess upon temperature, and possessed a large differential entropy of activation (-11 J K(-1) mol(-1)) for which the flexible host skeleton is likely to be responsible.

An organocatalytic quadruple cascade initiated by a Friedel-Crafts-type reaction is described. The (S)-diphenylprolinol trimethylsilyl ether catalyzed reaction yields highly functionalized cyclohexenecarbaldehydes bearing a 1,1-bis[4-(dialkylamino)phenyl]ethene moiety and three contiguous stereogenic centers. The reaction tolerates various functional groups and all products are obtained with ve...

BOM-tert-butylmethylphosphinite borane is an efficient electrophilic P-stereogenic transfer reagent for the synthesis of bulky tertiary phosphines. The novel methodology relies on a one-pot deprotection/substitution trivalent phosphinite that takes place with very high stereospecificity. potential this strategy demonstrated wide scope phosphines in excellent enantiomeric excess. was applied to ...

Chiral enrichment of serine is achieved in experiments that involve formation of serine octamers starting from non-racemic serine solutions. Serine octamers were generated by means of electrospray and sonic spray ionization of aqueous solutions of d(3)-L-serine (108 Da) and D-serine (105 Da) having different molar ratios of enantiomers. A cyclic process involving the formation of chirally-enric...

A copper-catalyzed method for the regioselective 1,3-dipolar cycloaddition of azomethine imines to terminal alkynes has been developed. Through the use of a chiral phosphaferrocene-oxazoline ligand, a wide range of substrates can be coupled to generate useful heterocycles in very good enantiomeric excess.

A P450 monooxygenase from Nocardia farcinica (CYP154A8) catalyses the stereo- and regioselective hydroxylation of n-alkanes, still a challenging task in chemical catalysis. In a biphasic reaction system, the regioselectivity for the C2-position of C7-C9 alkanes was over 90%. The enzyme showed strict S-selectivity for all tested substrates, with enantiomeric excess (ee) of up to 91%.

[reaction: see text] Benzaldehyde lyase from the Pseudomonas fluorescens catalyzes the reaction of aromatic aldehydes with methoxy and dimethoxy acetaldehyde and furnishes (R)-2-hydroxy-3-methoxy-1-arylpropan-1-one and (R)-2-hydroxy-3,3-dimethoxy-1-arylpropan-1-one in high yields and enantiomeric excess via acyloin linkage. Aromatic aldehydes and benzoins are converted into enamine-carbanion-li...

A highly enantioselective cyanohydrin synthesis with aromatic aldehydes using chiral lithium binaphtholate aqua or alcohol complexes has been developed and is a simple and inexpensive catalyst suitable for process chemistry to give gram-scale cyanohydrins successfully. Dramatic improvements in enantiomeric excess have been realized along with an interesting changeover in absolute stereochemistr...

Crystallization of a solution with high enantiomeric excess can generate a mixture of crystals of the desired enantiomer and the racemic compound. Using a mixture of S-/RS-ibuprofen crystals as a model, we demonstrated that magnetic levitation (MagLev) is a useful technique for analysis, separation and enantioenrichment of chiral/racemic products.