Triangulenium Ions: Versatile Organic Photoredox Catalysts for Green-Light-Mediated Reactions
We report their use as photocatalysts for the aerobic oxidative hydroxylation of arylboronic acids and the aerobic cross-dehydrogenative coupling reaction of N-phenyl-1,2,3,5-tetrahydroisoquinoline with nitromethane through reductive quenching. Furthermore, their potential as photoreduction catalysts has been demonstrated through the catalysis of an intermolecular atom-transfer radical addition via oxidative quenching. These transformations serve as benchmarks to highlight that the easily synthesized trianguleniums, congeners of the acridiniums, are versatile organic photoredox catalysts with applications in both photooxid...
Source: Synlett - September 18, 2023 Category: Chemistry Authors: Nowack, Marko H. Moutet, Jules Laursen, Bo W. Gianetti, Thomas L. Tags: cluster Source Type: research
Metal-Free Directed C –H Borylation of Indoles at the Sterically Congested C2 Position
Synlett DOI: 10.1055/a-2126-1750 During the past few decades, transition metal-catalyzed C–H borylation has been one of the most notable advances in synthetic chemistry and has been widely employed in the preparation of organoboron reagents. Due to economic and heavy-metal-residue concerns, there is significant interest in the development of metal-free processes to mimic metallic systems. Here, we disclose a highly efficient metal-free approach for the directed C–H borylation of C3-substituted indoles at the sterically congested C2 position that uses the inexpensive boron reagent BBr3. Compared with the conventional me...
Source: Synlett - September 18, 2023 Category: Chemistry Authors: Jiang, Wang Bai, Jingyi Lv, Jiahang Zhao, Yue Yan, Chaoguo Shi, Zhuangzhi Tags: cluster Source Type: research
Development of Novel Catalytic Direct Syntheses of N-Unsubstituted Ketimines and Their Applications to One-Pot Reactions
Conclusion [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents | Abstract | Full text (Source: Synlett)
Source: Synlett - September 18, 2023 Category: Chemistry Authors: Kondo, Yuta Morimoto, Hiroyuki Ohshima, Takashi Tags: account Source Type: research
Total Synthesis and Structure Revision of Saniculamoid D
We present the first asymmetric total synthesis of the norsesquiterpenoid saniculamoid D, from a previously known pure chiral imide, with a longest linear sequence of seven steps. The key highlight of the synthesis is the formation of the bicyclo[3.1.0]hexane moiety through the Julia–Kocienski olefination and Hodgson cyclopropanation. Notably, the NMR spectra and specific rotation value of the synthesized structure did not agree with those of the natural compound. However, a meticulous comparison of the data prompted the reassignment of the correct structure of saniculamoid D, which now corresponds to the structure initi...
Source: Synlett - September 15, 2023 Category: Chemistry Authors: Ota, Koichiro Kamaike, Kazuo Miyaoka, Hiroaki Tags: letter Source Type: research
Copper-Catalyzed Construction of Amide Linkages via Coupling between Unactivated Acids and Amines
Synlett DOI: 10.1055/a-2145-5986 Traditional amide linkage forming reactions by the coupling between an acid and an amine rely primarily on triggering the carboxylic acid counterpart with (over)stoichiometric activating agent(s) and generate unacceptable quantity of nondisposable waste, leading to poor atom economy. Herein, we report an efficient catalytic amide synthesis that proceeds through the in situ activation of the amine counterpart in the form of a reactive N-formyl amine species. The strategy gives an expedient access to an array of structurally varied amides, including dipeptides, from numerous genre of acids an...
Source: Synlett - September 14, 2023 Category: Chemistry Authors: Rahaman, Ajijur Bhadra, Sukalyan Tags: letter Source Type: research
