1942-45-6Relevant articles and documents
A highly active, heterogeneous catalyst for alkyne metathesis
Weissman, Haim,Plunkett, Kyle N.,Moore, Jeffrey S.
, p. 585 - 588 (2006)
(Chemical Equation Presented) An alkylidyne molybdenum amide complex is attached to nontoxic, amorphous silica to form a highly active, recyclable heterogeneous catalyst for alkyne metathesis. The catalyst does not undergo alkyne polymerization, can be utilized at a loading of 1 mol% at room temperature, and has shown unprecedented metathesis activity for the homodimerization of 2-propynylthiophene, a substrate that was previously problematic for alkyne metathesis.
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Bauer,D.P.,Macomber,R.S.
, p. 2640 - 2642 (1976)
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Staley,Doherty
, p. 288 (1969)
Selective terminal alkyne metathesis: Synthesis and use of a unique triple bonded dinuclear tungsten alkoxy complex containing a hemilabile ligand
Coutelier, Olivier,Nowogrocki, Guy,Paul, Jean-Francois,Mortreux, Andre
, p. 2259 - 2263 (2007)
The in situ synthesis of new alkyne metathesis catalysts is described, with particular emphasis on the search for tris-alkoxytungsten-based terminal alkyne metathesis. In that context, hemilabile, ether-containing alkoxy ligands have proved to be suitable and have led to the design and use of a sterically hindered hemilable ligand for the synthesis of a well-defined binuclear, triple-bonded W ≡ W complex. This complex is shown to be a highly active and selective catalyst precursor for terminal alkyne metathesis, and allows the unprecedented metathesis of phenylacetylene.
Rh(III)-Catalyzed [5 + 2] Oxidative Annulation of Cyclic Arylguanidines and Alkynes to 1,3-Benzodiazepines. A Striking Mechanistic Proposal from DFT
Martínez-Yá?ez, Nuria,Suárez, Jaime,Cajaraville, Ana,Varela, Jesús A.,Saá, Carlos
supporting information, p. 1779 - 1783 (2019/03/29)
A novel and mild Rh(III)-catalyzed [5 + 2] oxidative annulation between cyclic arylguanidines and alkynes efficiently affords 1,3-benzodiazepines (pentacyclic guanidines). The use of O2 as the sole oxidant in place of commonly used metal oxidants such as AgOAc clearly improves the efficiency of the oxidative annulation process. The mechanism of the cycloaddition most likely involves the formation of an eight-membered rhodacycle. DFT calculations support a striking mechanistic proposal for the [5 + 2] oxidative annulation.
Asymmetric Covalent Triazine Framework for Enhanced Visible-Light Photoredox Catalysis via Energy Transfer Cascade
Huang, Wei,Byun, Jeehye,R?rich, Irina,Ramanan, Charusheela,Blom, Paul W. M.,Lu, Hao,Wang, Di,Caire da Silva, Lucas,Li, Run,Wang, Lei,Landfester, Katharina,Zhang, Kai A. I.
supporting information, p. 8316 - 8320 (2018/06/29)
Complex multiple-component semiconductor photocatalysts can be constructed that display enhanced catalytic efficiency via multiple charge and energy transfer, mimicking photosystems in nature. In contrast, the efficiency of single-component semiconductor photocatalysts is usually limited due to the fast recombination of the photogenerated excitons. Here, we report the design of an asymmetric covalent triazine framework as an efficient organic single-component semiconductor photocatalyst. Four different molecular donor–acceptor domains are obtained within the network, leading to enhanced photogenerated charge separation via an intramolecular energy transfer cascade. The photocatalytic efficiency of the asymmetric covalent triazine framework is superior to that of its symmetric counterparts; this was demonstrated by the visible-light-driven formation of benzophosphole oxides from diphenylphosphine oxide and diphenylacetylene.
