metathesis as a phonological phenomenon in order to reverse segments has been focus of many studies. metathesis according to the range of application can be sporadic or regular. it links synchronic studies of language to diachronic ones and thereby has some consequences for phonological theory. the central goal of this paper is to elucidate the conditions under which metathesis occurs synchroni...

A salt metathesis reaction is a chemical process involving the exchange of bonds between two reacting chemical species, which results in the creation of products with similar or identical bonding affiliations. Hyperstructure theory is studied from the theoretical point of view and for its applications. In this paper, we provide some examples of hyperstructures associated with salt m...

Chemical biology relies on effective synthetic chemistry for building molecules to probe and modulate biological function. Olefin metathesis in organic solvents is a valuable addition to this armamentarium, and developments during the previous decade are enabling metathesis in aqueous solvents for the manipulation of biomolecules. Functional group-tolerant ruthenium metathesis catalysts modifie...

Over the past decade, ruthenium-mediated metathesis transformations, including cross-metathesis, ring-closing metathesis, enyne metathesis, ring-opening metathesis polymerization, and also tandem processes, belong to the most intensively studied reactions. Many applications of olefin metathesis in the synthesis of natural products have been recently described. Also in the field of steroid chemi...

Enyne metathesis is a bond reorganization of an alkene and an alkyne to produce a 1,3-diene (eqs 1 and 2 in Scheme 1). It has been used in both intramolecular and intermolecular applications. Enyne metathesis bears a mechanistic kinship to alkene metathesis; however, it is less-studied than alkene metathesis. The enyne bond reorganization is atom economical and is driven by the enthalpic stabil...

Olefin metathesis polymerization, in particularly ring-opening metathesis polymerization (ROMP), has been a popular topic of modern research. Two other types are acyclic diene metathesis polymerization (ADMET) and cyclopolymerization of diynes. To date, there has been no report on a metathesis polymerization utilizing more than one metathesis process. Herein, the concept of multiple olefin meta...

Whereas the olefin metathesis is recognized as a powerful tool to produce alkene, use of fluoroalkenes in metathesis-catalyzed reactions still remains major current challenge. Herein, we presented main developments that field both ring-closing and cross-metathesis, highlighting improvements these past years.

The catalytic performance of NHC-ligated Ru-indenylidene or benzylidene complexes bearing a tricyclohexylphosphine or a pyridine ligand in ring closing metathesis (RCM), cross metathesis, and ring closing enyne metathesis (RCEYM) reactions is compared. While the PCy₃ complexes perform significantly better in RCM and RCEYM reactions than the pyridine complex, all catalysts show similar activity ...

Olefin metathesis has emerged as a powerful tool in organic synthesis. The activating effect of an allylic hydroxy group in metathesis has been known for more than 10 years, and many organic chemists have taken advantage of this positive influence for efficient synthesis of natural products. Recently, the discovery of the rate enhancement by allyl sulfides in aqueous cross-metathesis has allowe...

Ru-based olefin metathesis catalysts containing carbohydrate-derived NHCs from glucose and galactose were synthesized and characterized by NMR spectroscopy. 2D-NMR spectroscopy revealed the presence of Ru-C (benzylidene) rotamers at RT and the rate of rotation was measured using magnetization transfer and VT-NMR spectroscopy. The catalysts were found to be effective at ring-opening metathesis p...