Ligand-Promoted γ-C(sp³)–H Arylation and Unsymmetrical Diarylation to Access Unnatural Amino Acid Derivatives

Abstract

A palladium(II)-catalyzed arylation of a γ-C(sp)-H bond of protected amino acid is explored. The monoarylation is promoted by the commercially available, inexpensive phenanthroline ligand, and toxic silver salt is replaced by earth-abundant Mn(III)acetate. Subsequently, a hitherto unknown unsymmetrical diarylation at the γ-position is accomplished under the modified reaction conditions. Ligands have a prominent influence in both mono- and unsymmetrical diarylations.

Site‐Selective C–H Bond Activation/Functionalization of Alpha‐Amino Acids and Peptide‐Like Derivatives

“…Motivated by Yu′s ligand‐enabled γ‐functionalization, the group of Jana lately developed an alternative ligand‐promoted diarylation protocol for the synthesis of unsymmetrical α‐amino acid derivatives 98 (Scheme ) . When the reaction was performed in absence of a ligand, a mixture of the mono and di‐arylated product was observed.…”

Diverse strategies for transition metal catalyzed distal C(sp3)–H functionalizations

“…Jana and coworkers have recently reported a 1,10-phenanthroline ligand enabled g-arylation of amino acids (Scheme 10). 15 Along with monoarylation, unsymmetrical diarylation was carried out utilizing a tricyclic ligand. Notably, inexpensive Mn(OAc) 3 dihydrate was utilized as oxidant in the reaction instead of expensive silver salts.…”

Bio-Inspired Ni(II) Porphyrin Dimers with a Bridging Diphenyl Moiety: Facile Synthesis and Molecular Inherent Chirality

“…Circu-lar dichroism (MCD) spectra were measured with a JASCO J-820 equipment. -10,15,20-triphenylporphyrin (1). Nitrosonitric acid (3.2 mL) was slowly added to 300 mL of CH 2 Cl 2 solution of 5,10,15,20-tetrahenylporphyrin (3.00 g, 4.88 mmol), and the mixture was stirred at 0-5°C in an ice-bath for 4 h. The reaction mixture was neutralized with ammonia solution to ca.…”

“…After removal of the organic solvent, the residue was purified through recrystallization by adding MeOH to the CH 2 Cl 2 solution to afford pure 5-p-aminophenyl-10,15,20-triphenylporphyrin 1 as a purple solid in 87.3 % yield (767 mg). 1 Synthesis of trans-1. Trans-1 was isolated from the reaction mixture that of synthesis of cis-1, and the target compound was obtained in a 33.…”

“…As the key components in human genes and proteins, amino acids, the natural organic compounds containing amine (-NH 2 ) and carboxyl (-COOH) functional groups along with a side chain (R group) specific to each amino acid, have a great importance in life processes. [1][2] Also, reactions between chiral amine and carboxyl derivatives which forming amide-bonds that repeat the basic chemical processes of protein four-level construction. [3][4] In addition, chirality has been the subject of ongoing research interest in the pharmacy, food, and chemicals industries.…”