Enantioselective Synthesis of Arylglycines via Pd-Catalyzed Coupling of Schöllkopf Bis-Lactim Ethers with Aryl Chlorides.

Arylglycines are important pharmacophores present in several top-selling drugs. This compound class has now been made accessible from abundant aryl chlorides by a Pd-catalyzed Schöllkopf-type amino acid synthesis. In the presence of the catalyst methylnaphthyl(XPhos)-palladium bromide, the base lithium 2,2,6,6-tetramethylpyrrolidide and the additive ZnCl , tert-leucine-derived bis-lactim ethers were efficiently arylated at room temperature, reaching yields of 95 % and diastereoselectivities of 98 : 2.

Ru-Catalyzed ()-Specific -C-H Alkenylation of Arenecarboxylic Acids by Coupling with Alkenyl Bromides.

In the presence of [-cymene)RuCl], ()-configured alkenyl bromides couple with aromatic carboxylates to form -vinylbenzoic acids. This C-H vinylation proceeds in high yields without any activating phosphine ligands and has an excellent functional group tolerance. Starting from commonly available (/ )-mixtures of alkenyl bromides, ()-configured vinyl arenes or dienes are formed exclusively.

A Nickel(II)-Mediated Thiocarbonylation Strategy for Carbon Isotope Labeling of Aliphatic Carboxamides.

A series of pharmaceutically relevant small molecules and biopharmaceuticals bearing aliphatic carboxamides have been successfully labeled with carbon-13. Key to the success of this novel carbon isotope labeling technique is the observation that C-labeled Ni -acyl complexes, formed from a CO insertion step with Ni -alkyl intermediates, rapidly react in less than one minute with 2,2'-dipyridyl disulfide to quantitatively form the corresponding 2-pyridyl thioesters. Either the use of C-SilaCOgen or C-COgen allows for the stoichiometric addition of isotopically labeled carbon monoxide.