2734-70-5Relevant articles and documents
Nickel(ii)-catalyzed asymmetric thio-Claisen rearrangement of α-diazo pyrazoleamides with thioindoles
Yang, Wei,Lin, Xiaobin,Zhang, Yongyan,Cao, Weidi,Liu, Xiaohua,Feng, Xiaoming
, p. 10002 - 10005 (2020/09/15)
A nickel(ii) catalyzed enantioselective thio-Claisen rearrangement of α-diazo pyrazoleamides with thioindoles was realized with modified chiral N,N′-dioxide ligands, affording a variety of C3-substituted indole derivatives in high yields (up to 95%) with excellent enantioselectivities (up to 96% ee) under mild reaction conditions. A possible transition state model was proposed based on previous reports and the X-ray crystal structure of the catalyst.
Photocatalytic Cleavage of Aryl Ether in Modified Lignin to Non-phenolic Aromatics
Li, Hongji,Bunrit, Anon,Lu, Jianmin,Gao, Zhuyan,Luo, Nengchao,Liu, Huifang,Wang, Feng
, p. 8843 - 8851 (2019/09/30)
Depolymerization of lignin meets the difficulty in cleaving the robust aryl ether bond. Herein, through installing an internal nucleophile in the β-O-4′ linkage, the selective cleavage of aryl ether was realized by the intramolecular substitution on aryl rings affording non-phenolic arylamine products. In particular, nitrogen-modified lignin models and lignin samples were employed to generate the iminyl radical under photocatalytic reduction, which acted as the internal nucleophile inducing aryl migration from O to the N atom. The following hydrolysis released primary arylamines and α-hydroxy ketones. Mechanism studies including electron spin resonance (ESR), fluorescence quenching experiments, and density functional theory (DFT) calculations proved the aryl migration pathway. This method enables access to non-phenolic arylamine products from lignin conversion.
Kolbe-Schmitt type reaction under ambient conditions mediated by an organic base
Sadamitsu, Yuta,Okumura, Akira,Saito, Kodai,Yamada, Tohru
supporting information, p. 9837 - 9840 (2019/08/20)
The combined use of an organic base for resorcinols realized a Kolbe-Schmitt type reaction under ambient conditions. When resorcinols (3-hydroxyphenol derivatives) were treated with DBU under a carbon dioxide atmosphere, nucleophilic addition to carbon dioxide proceeded to afford the corresponding salicylic acid derivatives in high yields.
