Alkyne metathesis by molybdenum and tungsten alkylidyne complexes is now ~45 years old. Progress in the practical aspects of alkyne metathesis reactions with well-defined complexes, as well as applications, in the last decade, guarantees that it is destined to become a useful method for the synthesis of organic molecules.

The catalytic properties of olefin metathesis ruthenium complexes bearing N-heterocyclic carbene ligands with stereogenic centers on the backbone are described. Differences in catalytic behavior depending on the backbone configurations of symmetrical and unsymmetrical NHCs are discussed. In addition, an overview on asymmetric olefin metathesis promoted by chiral catalysts bearing C₂-symmetric a...

Poly (ether-block-amide) /poly (ethylene glycol)/ carbon nanotubes mixed matrix membranes have been successfully fabricated using solvent evaporation method to determine the effect of ethylene oxide groups on the performance of produced membranes. The effects of CNTs (2-8 wt%) and PEG (up to 50 wt%)were investigated in both single and mixed gas test setup in different temperature and pressure. ...

the process of ethylene production from ethane dehydrogenation is one of the interesting processes in the field of conversion the petroleum light gases to the valuable products. in this process, the outlet gaseous product is a combination of ethylene, ethane and hydrogen. effective separation techniques are required for separation of ethylene from unreacted ethane. here a new adsorbent approach...

Key words (–)-stemoamide - Stemona alkaloids Evans aldol reaction cross metathesis Riley oxidation Staudinger

Allyl sulphides are reactive substrates in ruthenium-catalysed olefin metathesis reactions, provided each substrate is matched with a suitable catalyst. A profile of catalyst activity is described, along with the first demonstration of allyl sulphides as traceless promoters in relayed ring-closing metathesis reactions.

[reaction: see text] An enantioselective total synthesis of (-)-mucocin has been completed. A combination of asymmetric glycolate aldol additions and ring closing metathesis reactions were exploited to construct the C18-C34 and C7-C17 fragments. A selective cross-metathesis reaction was employed as the key step to couple two complex fragments.

since the discovery of macc as a major metabolite of both endogenous and exogenously applied acc, it has become evident that the formation of macc from acc can act to regulate ethylene production in certain tissues. hence, it was suggested that macc could serve as an indicator of water-stress history in plant tissues. the accurate quantification of macc in plant tissues is essential for the und...

Bis(1,4-diamino-1,2,4-triazolium) sulfate (1) was obtained from the corresponding chloride by ion metathesis using Ag2SO4. Further metathesis with barium 5,51-azotetrazolate yielded bis(1,4-diamino-1,2,4-triazolium) 5,51-azotetrazolate (2). Numerous NH ̈ ̈ ̈N and NH ̈ ̈ ̈O interactions were identified in the crystal structures of 1 and 2. Both compounds undergo exothermal decomposition upon heating.

A series of sugar-derived spiroaminals has been synthesized by utilizing cross metathesis, ring closing metathesis and lactamization reactions as key steps from 1-C-alkylated glycosyl azides and important correlations in the spectral data between spiroaminals and their respective anomers are reported.