α‐Amino Acids: An Emerging Versatile Synthon in Visible Light‐Driven Decarboxylative Transformations

Abstract

Abstractα‐Amino acids have been widely recognized as environmental‐benign and non‐fossil carbon sources both in biological and synthetic chemistry. In recent years, with the remarkable development of visible‐light photocatalysis in organic synthesis, α‐amino acid and its derivatives have received tremendous attention as radical precursors via photocatalyzed decarboxylation, thus realizing diverse aminoalkylated transformations or constructions of novel N‐bearing heterocyclic motifs by taking advantage of N‐atoms from α‐amino acid. This review aims to provide a comprehensive update on the recent exploitation of α‐amino acids in visible light photocatalysis, with particular emphasis on the types of α‐amino acids employed and their distinct mechanisms applied wherein.

TEMPO/O2 Synergistically Mediated BiBrO‐Photocatalyzed Decarboxylative Phosphorylation of N‐Arylglycines

“…Performing the model reaction with other solvents (MeCN, EtOH, EtOAc and THF) gave inferior results (entry 8). Varying the wavelength of LED light (purple LED, green LED and white LED) reduced the reaction yield (entries [9][10][11]. Conducting the reaction at room temperature gave 3 aa in 45 % yiled (entry 12).…”

“…In this respect, α-amino acid and its derivatives have been widely applied in synthesis chemistry given its low cost and stable chemical properties. [11] Among various α-amino acid derivatives, N-aryl glycines are extensively utilized as α-aminomethyl radical precursor for the construction of carbon-carbon and carbon-heteroatom bonds. [12] With our continuing interest in photocatalysis [13] , herein, we report the synthesis of α-amino phosphinoxides through TEMPO/O 2 synergistically mediated BiBrO-photocatalyzed decarboxylative phosphorylation of Narylglycines with diarylphosphine oxides (Scheme 1b).…”

Modular synthesis of congested β2,2-amino acids via the merger of photocatalysis and oxidative functionalisations

“…11 The proposed approach proceeds in a two-step sequence (Fig. 1B): ( 1 ) light-mediated Giese-type reaction 12 between alkylidenemalononitriles ( A ) 13,14 – readily synthesised via Knoevenagel condensation – 15 and α-amino acids, 16 and ( 2 ) oxidation of the resulting β-quaternary malononitriles 17 ( B ) to access the targeted β 2,2 -amino acid analogues ( C ).…”

Ferrocene/air double-mediated FeTiO3-photocatalyzed semi-heterogeneous annulation of quinoxalin-2(1H)-ones in EtOH/H2O

“…The visible-light photocatalytic decarboxylative functionalization of amino acid derivatives has emerged as an efficient and sustainable tool in modern synthetic chemistry. 6 During the past few years, impressive achievements have been developed in applying N -arylglycines as α-aminomethyl radical precursors for constructing various high value-added chemicals. 7 Imidazo[1,5- a ]quinoxalinones are a vital class of fused imidazo[1,5- a ]-N-heteroarenes as they have promising biological activities and physicochemical properties.…”