570-23-0Relevant articles and documents
Functional Group-Directed Photochemical Reactions of Aromatic Alcohols, Amines, and Thiols Triggered by Excited-State Hydrogen Detachment: Additive-free Oligomerization, Disulfidation, and C(sp2)-H Carboxylation with CO2
Abe, Kanae,Nakada, Akinobu,Matsumoto, Takeshi,Uchijyo, Daiki,Mori, Hirotoshi,Chang, Ho-Chol
, p. 959 - 969 (2021)
Exploring new types of photochemical reactions is of great interest in the field of synthetic chemistry. Although excited-state hydrogen detachment (ESHD) represents a promising prospective template for additive-free photochemical reactions, applications of ESHD in a synthetic context remains scarce. Herein, we demonstrate the expansion of this photochemical reaction toward oligomerization, disulfidation, and regioselective C(sp2)-H carboxylation of aromatic alcohols, thiols, and amines. In the absence of any radical initiators in tetrahydrofuran upon irradiation with UV light (λ = 280 or 300 nm) under an atmosphere of N2 or CO2, thiols and catechol afforded disulfides and oligomers, respectively, as main products. Especially, the photochemical disulfidation proceeded highly selectively with the NMR and quantum yields of up to 69 and 0.46%, respectively. In stark contrast, the photolysis of phenylenediamines and aminophenols results in photocarboxylation in the presence of CO2 (1 atm). p-Aminophenol was quantitatively carboxylated by photolysis for 17 h with a quantum yield of 0.45%. Furthermore, the photocarboxylation of phenylenediamines and aminophenols proceeds in a highly selective fashion on the aromatic C(sp2)-H bond next to a functional group, which is directed by the site-selective ESHD of the functional groups for the formation of aminyl and hydroxyl radicals.
3-process for the preparation of amino-salicylic acid
-
Paragraph 0024; 0027-0028, (2016/10/08)
The invention relates to a novel preparation method of 3-aminosalicylic acid. The novel preparation method is characterized in that a salicylic acid compound I as an initial raw material having a general formula shown in the description and a nitration agent undergo a reaction to produce a 3-nitrosalicylic acid compound II having a general formula shown in the description, and the 3-nitrosalicylic acid compound II undergoes nitryl catalytic hydrogenation reduction and dehalogenation hydrogenolysis reactions in the presence of an effective dose of a catalyst and hydrogen donors so that 3-aminosalicylic acid is produced.
Regioselective ortho-carboxylation of phenols catalyzed by benzoic acid decarboxylases: A biocatalytic equivalent to the Kolbe-Schmitt reaction
Wuensch, Christiane,Gross, Johannes,Steinkellner, Georg,Lyskowski, Andrzej,Gruber, Karl,Glueck, Silvia M.,Faber, Kurt
, p. 9673 - 9679 (2014/03/21)
The enzyme catalyzed carboxylation of electron-rich phenol derivatives employing recombinant benzoic acid decarboxylases at the expense of bicarbonate as CO2 source is reported. In contrast to the classic Kolbe-Schmitt reaction, the biocatalytic equivalent proceeded in a highly regioselective fashion exclusively at the ortho-position of the phenolic directing group in up to 80% conversion. Several enzymes were identified, which displayed a remarkably broad substrate scope encompassing alkyl, alkoxy, halo and amino- functionalities. Based on the crystal structure and molecular docking simulations, a mechanistic proposal for 2,6-dihydroxybenzoic acid decarboxylase is presented.
