Palladium-catalyzed borylation of l-tyrosine triflate derivative with pinacolborane: practical route to 4-borono-l-phenylalanine (l-BPA) derivatives

Masuda Borylation–Suzuki Coupling (MBSC) Sequence: A One-Pot Process to Access Complex (hetero)Biaryls

The direct formation of (hetero)biaryls from readily available (hetero)aryl halides under mild reaction conditions can be efficiently achieved through the Masuda borylation–Suzuki coupling (MBSC) sequence. The MBSC sequence catenates Pd-catalyzed Masuda borylation and Suzuki coupling into a one-pot process, giving access to diverse symmetrically and unsymmetrically substituted scaffolds. (Hetero)biaryls are ubiquitous structural motifs that appear in natural products, pharmaceutically relevant scaffolds, functional dyes, and several other structures. This review summarizes the development of the MBSC sequence and its improvements over the past two decades.

Synthesis of Isotopically Labeled, Spin-Isolated Tyrosine and Phenylalanine for Protein NMR Applications

Isotopically labeled amino acids are widely used to study the structure and dynamics of proteins by NMR. Herein we describe a facile, gram-scale synthesis of compounds 1b and 2b under standard laboratory conditions from the common intermediate 7. 2b is obtained via simple deprotection, while 1b is accessed through a reductive deoxygenation/deuteration sequence and deprotection. 1b and 2b provide improved signal intensity using lower amounts of labeled precursor and are alternatives to existing labeling approaches.

Functionalization of aromatic amino acids via direct C-H activation: generation of versatile building blocks for accessing novel peptide space

Functionalized alpha-amino acid building blocks have been prepared in good yield with high regiocontrol and preservation of stereochemistry via iridium-catalyzed borylation of suitably protected aromatic alpha-amino acid derivatives. The utility of these systems in peptide couplings and Suzuki reactions has been demonstrated.