Palladium(0)/PAr3 -Catalyzed Intermolecular Amination of C(sp(3) )H Bonds: Synthesis of β-Amino Acids.

An intermolecular C(sp(3))-H amination using a Pd(0) /PAr3 catalyst was developed. The reaction begins with oxidative addition of R2 N-OBz to a Pd(0) /PAr3 catalyst and subsequent cleavage of a C(sp(3))-H bond by the generated Pd-NR2 intermediate. The catalytic cycle proceeds without the need for external oxidants in a similar manner to the extensively studied palladium(0)-catalyzed C-H arylation reactions.

Ligand-enabled β-C-H arylation of α-amino acids using a simple and practical auxiliary.

Pd-catalyzed β-C-H functionalizations of carboxylic acid derivatives using an auxiliary as a directing group have been extensively explored in the past decade. In comparison to the most widely used auxiliaries in asymmetric synthesis, the simplicity and practicality of the auxiliaries developed for C-H activation remains to be improved. We previously developed a simple N-methoxyamide auxiliary to direct β-C-H activation, albeit this system was not compatible with carboxylic acids containing α-hydrogen atoms.

Synthesis of fluorescence-labeled sphingosine and sphingosine 1-phosphate; effective tools for sphingosine and sphingosine 1-phosphate behavior.

A fluorescence-labeled sphingosine and sphingosine 1-phosphate have been successfully synthesized from the oxazolidinone methyl ester derived from glycidol via monoalkylation and the stereoselective reduction of the resulting ketone. The labeled sphingosine was converted into its phosphate by treatment with sphingosine kinase 1 (SPHK1) from mouse, and in platelets, and it was incorporated into the Chinese Hamster Ovarian (CHO) cells. In addition, MAPK was activated by NBD-Sph-1-P through Edg-1, Sph-1-P receptor.