The discovery of highly active catalysts and the success of ionic liquid immobilized systems have accelerated attention to a new class of cationic metathesis catalysts. We herein report the facile syntheses of cationic ruthenium catalysts bearing bulky phosphine ligands. Simple ligand exchange using silver(i) salts of non-coordinating or weakly coordinating anions provided either PPh3 or chelat...

Olefin metathesis as a catalytic process constantly gains interest among organic chemists. Over the last decade, it became an efficient tool to accomplish the synthesis of many complex molecules. The development of new well-defined catalysts and continuous examination of novel ligands led to the establishment of metathesis methodology in a group of widespread chemical transformations. Not only ...

An analog of mycothiazole and pseudotrienic acid B were synthesized efficiently by using ring-closing metathesis or cross-metathesis as key reactions.

A series of cyclometalated Z-selective ruthenium olefin metathesis catalysts with alterations to the N-heterocyclic carbene (NHC) ligand were prepared. X-Ray crystal structures of several new catalysts were obtained, elucidating the structural features of this class of cyclometalated complexes. The metathesis activity of each stable complex was evaluated, and one catalyst, bearing geminal dimet...

Catalytic asymmetric ring-opening metathesis (AROM) provides an efficient method for the synthesis of a variety of optically enriched small organic molecules that cannot be easily prepared by alternative methods. The development of Mo-catalyzed AROM transformations that occur in tandem with ring-closing metathesis are described. The utility of the Mo-catalyzed AROM/ring-closing metathesis is de...

A tandem olefin metathesis/oxidative cyclization has been developed to synthesize 2,5-disubstituted tetrahydrofuran (THF) diols in a stereocontrolled fashion from simple olefin precursors. The ruthenium metathesis catalyst is converted into an oxidation catalyst in the second step and is thus responsible for both catalytic steps. The stereochemistry of the 1,5-diene intermediate can be controll...

A direct and scalable route to γ-keto-α,β-unsaturated esters, useful intermediates in medicinal chemistry and natural products synthesis, is reported. The key step involves the use of Grubbs' second-generation olefin metathesis catalyst for cross-metathesis of alkyl acrylates and 2° allylic alcohols. The metathesis step is followed by oxidation to give the desired products in high yield on scal...

The Z-selective cross metathesis of allylic-substituted olefins is explored with recently developed ruthenium-based metathesis catalysts. The reaction proceeds with excellent stereoselectivity for the Zisomer (typically >95%) and yields of up to 88% for a variety of allylic substituents. This includes the first synthesis of Z-a,b-unsaturated acetals by cross metathesis and their elaboration to ...

the focus of this paper lies on abu ali farsi's general views on the development of linguistic phenomena including synonymity, antonymity, parallelism, lexical assimilation, and metathesis. the paper sheds light on the views erroneously attributed to abu ali farsi, somehow analyzing and rectifying misinterpretations given to his views.

The literature of olefin metathesis by heterogeneous supported catalysts, both industrial-type supported metal oxides (ReOx/Al2O3, ReOx/(SiO2−Al2O3), MoOx/SiO2, MoOx/Al2O3, MoOx/(SiO2−Al2O3), WOx/SiO2, and WOx/ (SiO2−Al2O3)) and supported organometallic complexes, is comprehensively reviewed. The focus of this Review is supported metal oxide catalysts, but the well-defined supported organometal...