A divergent strategy is presented for the synthesis of 1,3-di- and 1,3,4-trisubstituted beta-carbolines through an unprecedented one-pot triple-orthogonal-metal relay catalysis, and 1,3-disubstituted ...4-hydroxy-beta-carbolines through a one-pot bimetallic relay catalysis from readily accessible 3-(2-aminophenyl)-5-hexenyn-3-ols. These strategies were elaborated to enable the synthesis of benzofuro2,3-cpyridines, benzothieno2,3-cpyridines, and isoquinolines, which otherwise require multistep synthesis.
Reaction of 5,6‐dihydro‐4H‐pyrrolo3,2,1‐ijquinoline‐1,2‐dione (3) with two equivalents of cyclic 1,3‐dicarbonyl compounds under acid catalysis generates spiro4H‐pyran‐3,3′‐oxindoles 7. In contrast, ...though base catalysis also achieves double addition, the final products 8 result from subsequent ring opening of the five‐membered lactam via intramolecular attack by enolate; these products can be converted into the spiro4H‐pyran‐3,3′‐oxindoles by treatment with acid.
The acid-catalyzed rearrangement of epoxides 3a, 4a, 6a, and 7a derived from beta-himachalene, the major constituent of Cedrus atlantica essential oil, has been studied using various Lewis and ...Bronsted acids. Several new enantiomerically pure ketones were obtained in good yields and high selectivities. All products obtained were fully characterized by .sup.1H and .sup.13C NMR, and the mechanistic explanations for their formation were proposed.
Armido Studer
European journal of organic chemistry,
July 13, 2018, Volume:
2018, Issue:
26
Journal Article
Peer reviewed
“We are currently trying to push the boundaries of ‘electron‐catalysis’.” Find out more about this author's research at https://doi.org/10.1002/ejoc.201800583.
“We are currently trying to push the ...boundaries of ‘electron‐catalysis’.” Find out more about this author's research at https://doi.org/10.1002/ejoc.201800583.
“The Catalysis Society of South Africa (CATSA) is established to promote all scientific and technical aspects of catalysis in South Africa, through the promotion of dialogue and the development of ...students and young researchers.” This and more about the Catalysis Society of South Africa can be found in this issue's Society Profile.
The endeavor of mastering “Nature-like Multicatalysis” in vitro has inspired chemists to develop catalytic systems comprising a variable number of catalysts in one-pot. Having been pioneered in the ...primitive stages (particularly unary and binary catalysis), the field has witnessed the inception of “Ternary Catalysis” described as the concept of harnessing an ensemble effect of three discrete catalysts in one-pot. Although the concept is nascent, it has already demonstrated its invaluable importance in terms of producing novel reactivity, prodigious selectivity, and efficiency. As evident from the presented documentation, the number of pertinent reports utilizing ternary catalysis has drastically increased in the past few years; however, these reports remain scattered in the literature. The conceptualization and unambiguous catalyst-dependent classification presented herein provides an imperative unified approach to assemble and categorize all such reports which have remained missing by far. Special emphasis has been given to mechanistic analysis clearly disclosing the beauty of ternary catalysis. For the better understanding of the concept, a succinct description of challenges and problems associated in the development of a ternary catalytic system has been presented. In addition, the Review briefly discusses some of the unsolved problems and possible developments in this field.
The cover picture shows that the quest for rapid syntheses of fluorophores, necessary to establish structure–property relationships, can be efficiently and effectively fulfilled by ...metal‐catalysis‐initiated chromogenic multicomponent reactions, representing a reactivity‐based concept in diversity‐oriented synthesis. Besides solution‐luminescent materials also solid‐state‐emissive chromophores and the young class of aggregation‐induced emission dyes can be readily accessed, enabling one‐pot syntheses of functional ρ‐systems for photonic and electronic materials. Details are presented in the Microreview by L. Levi and T. J. J. Müller on p. 2907 ff.
“The Catalysis Society of Australia is a scientific association with the principal mission to further education in the study of catalysis, including the technology and application in all branches of ...science and engineering.” This and more about the Catalysis Society of Australia can be found in this issue's Society Profile.
Asymmetric Ion-Pairing Catalysis Brak, Katrien; Jacobsen, Eric N.
Angewandte Chemie (International ed.),
January 7, 2013, Volume:
52, Issue:
2
Journal Article
Peer reviewed
Open access
Charged intermediates and reagents are ubiquitous in organic transformations. The interaction of these ionic species with chiral neutral, anionic, or cationic small molecules has emerged as a ...powerful strategy for catalytic, enantioselective synthesis. This review describes developments in the burgeoning field of asymmetric ion‐pairing catalysis with an emphasis on the insights that have been gleaned into the structural and mechanistic features that contribute to high asymmetric induction.
Framing the field, this review provides an overview of four ion‐pairing strategies that have emerged for asymmetric catalysis of transformations proceeding through charged intermediates or reagents (see picture). Particular emphasis is placed on the mechanistic features that enable high asymmetric induction in these systems.
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