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.

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.

[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.

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.

This review covers H–H bond cleavage of dihydrogen (H2) mediated by structurally well-defined rare-earth metal (scandium, yttrium and lanthanides) complexes, their applications in homogenous catalysis, such as catalytic hydrogenation unsaturated organic molecules. Depending on the mechanism cleavage, this is organized two parts: (1) ?-bond metathesis, (2) non-?-metathesis H2 activation. The lat...

A highly functionalized intermediate in the synthesis of Taxol has been synthesized, which features the tricyclic core and the required oxygen substituents at C1, C2, C7, C10, and C13. The key step, a ring-closing dienyne metathesis (RCDEYM) reaction, has been thoroughly optimized to favor the tricyclic product over the undesired bicyclic product resulting from diene metathesis.

Phosphine-free ruthenium benzylidene complexes containing imidazole ligands are reported. These catalysts effective for ring-closing metathesis (RCM) and cross-metathesis (CM) reactions at high temperatures, where the more widely used phosphine-containing N-heterocyclic carbene-based show side reactions. This discovery opens up a pathway to develop selective requiring harsh conditions.