1060-92-0Relevant articles and documents
Organocatalytic Claisen rearrangement: Theory and experiment
Kirsten, Martin,Rehbein, Julia,Hiersemann, Martin,Strassner, Thomas
, p. 4001 - 4011 (2007)
(Chemical Equation Presented) A combined computational and experimental study on the Claisen rearrangement of a 2-alkoxycarbonyl-substituted allyl vinyl ether in the presence of thioureas as potential noncovalent organocatalysts has been performed. DFT ca
Organophotocatalysis: Insights into the Mechanistic Aspects of Thiourea-Mediated Intermolecular [2+2]Photocycloadditions
Vallavoju, Nandini,Selvakumar, Sermadurai,Pemberton, Barry C.,Jockusch, Steffen,Sibi, Mukund P.,Sivaguru, Jayaraman
, p. 5446 - 5451 (2016)
Mechanistic investigations of the intermolecular [2+2] photocycloaddition of coumarin with tetramethylethylene mediated by thiourea catalysts reveal that the reaction is enabled by a combination of minimized aggregation, enhanced intersystem crossing, and
Hydrogen-Bond Catalysis of Imine Exchange in Dynamic Covalent Systems
Schaufelberger, Fredrik,Seigel, Karolina,Ramstr?m, Olof
supporting information, p. 15581 - 15588 (2020/10/02)
The reversibility of imine bonds has been exploited to great effect in the field of dynamic covalent chemistry, with applications such as preparation of functional systems, dynamic materials, molecular machines, and covalent organic frameworks. However, acid catalysis is commonly needed for efficient equilibration of imine mixtures. Herein, it is demonstrated that hydrogen bond donors such as thioureas and squaramides can catalyze the equilibration of dynamic imine systems under unprecedentedly mild conditions. Catalysis occurs in a range of solvents and in the presence of many sensitive additives, showing moderate to good rate accelerations for both imine metathesis and transimination with amines, hydrazines, and hydroxylamines. Furthermore, the catalyst proved simple to immobilize, introducing both reusability and extended control of the equilibration process.
Mechanism-Based Condition Screening for Sustainable Catalysis in Single-Electron Steps by Cyclic Voltammetry
Liedtke, Theresa,Spannring, Peter,Riccardi, Ludovico,Gans?uer, Andreas
supporting information, p. 5006 - 5010 (2018/03/30)
A cyclic-voltammetry-based screening method for Cp2TiX-catalyzed reactions is introduced. Our mechanism-based approach enables the study of the influence of various additives on the electrochemically generated active catalyst Cp2TiX, which is in equilibrium with catalytically inactive [Cp2TiX2]?. Thioureas and ureas are most efficient in the generation of Cp2TiX in THF. Knowing the precise position of the equilibrium between Cp2TiX and [Cp2TiX2]? allowed us to identify reaction conditions for the bulk electrolysis of Cp2TiX2 complexes and for Cp2TiX-catayzed radical arylations without having to carry out the reactions. Our time- and resource-efficient approach is of general interest for the design of catalytic reactions that proceed in single-electron steps.