Current Organic Chemistry - Volume 17, Issue 22, 2013

This review provides an overview of the studies dealing with the use of cationic ruthenium complexes in olefin metathesis reactions and includes mechanistic aspects relative to active species behaviors.

The evolution of olefin metathesis catalysts throughout the past six decades has been driven by the need to accommodate more complex, more challenging and more sophisticated applications with this elegant and popular synthetic technology. These challenges have led to a myriad of catalyst designs, in particular the Grubbs-type Ru-alkylidene complexes with their superior tolerance of functional groups and high metat Read More

Immobilization of ruthenium metathesis catalysts on solid supports has attracted much attention in recent years since it opens up the possibility for easy catalyst–product separation and catalyst reuse as well as reduction of the residual ruthenium content in the organic product. The state of the art on immobilization of ruthenium based metathesis initiators on solid supports is surveyed in this review. In addition, a comparison of t Read More

Synthesis of biologically active compounds is of paramount importance to the biomedical sciences for the development of novel therapeutic agents. Such substances often feature various types of unique and complex structures, which make them challenging targets for synthetic efforts. Their total synthesis offers the chance to implement the use of newly developed, efficient and highly selective synthetic procedures and/ Read More

α,β-Unsaturated γ- and δ-lactones are important classes of five- and six-membered heterocycles largely present in biologically active compounds of natural and unnatural origin, for which the ring-closing metathesis approach has disclosed simplified synthetic strategies en route or in the final step toward the target molecules. Following from early examples of formation of macrolide rings, this account describes the RCM reacti Read More

This paper surveys recent advances in valorization of transition-metal-catalyzed enyne metathesis as key events in the total synthesis of naturally occurring compounds of biological and medicinal importance. Special attention is devoted to methodologies based on dienyne ring-closing metathesis (RCM) applied in tandem and sequential processes, on relay ring-closing metathesis (RRCM), ringrearrangement metathesis ( Read More

This article provides a fairly comprehensive overview on olefin metathesis reactions applied as pivotal steps in the total syntheses of indolizidine alkaloids belonging to the families of castanospermine, deoxycastanospermine and diastereomers thereof, natural or non-natural compounds that play multiple roles in biological processes. A well-balanced mixture of topics is proposed, covering most relevant traits of their biological Read More

This mini-review describes approaches to conduct olefin metathesis catalysed by transition metal catalysts in continuous flow (CF) mode. In this context extremely high efficiency of well defined Mo and Ru catalysts is highlighted.

Acyclic diene metathesis polymerization (ADMET) has taken a long path from its beginnings with Schrock catalyst and unfunctionalized dienes to use of Grubbs catalysts with nearly unlimited choices for pendant groups and chain composition. This review covers synthesis of model linear polyethylene via ADMET polymerization, synthesis of polymers from green feed stocks, and the effect of spacer length on morphology a Read More

The concept for preparing functional, high molecular weight poly(olefin)s via tandem ring-opening metathesis / vinyl insertion polymerization is reviewed. It is based on a reversible α-H-addition/α-H-elimination process occurring in tailor-made catalysts. Copolymerization of ethylene with cyclic olefins with these catalysts yields poly(olefin)s with double bonds in the main chain. These can then be converted into various func Read More

We describe various non-matathetic reactions catalyzed by metathesis catalysts. These examples include: isomerization of olefins, dehydrogenative oxidation, dihydroxylation, allylic alcohol to methyl ketone conversion, dimerization, vinylation of acetylenes, hydrosilylation, Kharasch addition, cyclopropanation, cycloisomerization, hydrogenation, deprotection of N- or O-allyl groups, [2+2+2] cyclotrimerization, [3+2] and [4+2] Read More

Olefin metathesis catalysed by solid systems has found a number of industrial applications. During the last decade, heterogeneous catalysts for olefin metathesis were comprehensively studied by experimental and theoretical methods. A great progress has been achieved in the field of both conventional and well-defined catalytic systems. The computational approach, taking advantage of growing computer power, enabled f Read More