Efficient and selective formation of macrocyclic disubstituted z alkenes by ringclosing metathesis rcm reactions catalyzed by mo or wbased monoaryloxide pyrrolide map complexes. Nonproductive events in ringclosing metathesis using ruthenium catalysts ian c. For their elucidation of the reaction mechanism and their. Enantioselective ring expansion of prolinols and ringclosing metathesis. However, there are a number of unobserved yet implied intermediates assumed to exist. Ringclosing metathesis rcm and ringopening metathesis romp dr. The reactions are generally reversible and under thermodynamic control. Grubbs the arnold and mabel beckman laboratory of chemical synthesis, division of chemistry and chemical engineering, california institute of technology, pasadena, california 91125. Ringopening metathesis polymerization romp uses metathesis catalysts to generate polymers from cyclic olefins. Applications to total syntheses of epilachnene, yuzu lactone, ambrettolide, epothilone c, and nakadomarin a. The ringclosing metathesis reaction has also been applied to the formation of a sevenmembered cyclic sulfonamide. In this tutorial we go over the organometallic catalysed olefin metathesis reaction with particular emphasis on the chauvin. Application of the method to the synthesis of the natural product fusanolide a suggests that the originally.
Deryn fogg at the university of ottawa, where he is developing new catalysts for applications in olefin metathesis and exploring the mechanistic behavior associated with ringchain equilibria in ringclosing metathesis. Romp is most effective on strained cyclic olefins, because the relief of ring strain is a major driving force for the reaction cyclooctene and norbornenes are excellent monomers for romp, but cyclohexene is very reluctant to form any significant amount of polymer. Read ring closing metathesis, cheminform on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Initial studies investigated the stereoenrichment of. It offers an insight into various synthetic targets and approaches and provides information on the evolution of catalysts as powerful tools enabling the use of incr. As a consequence, little is known about the energetics of all the processes involved. What is the abbreviation for ringclosing metathesis. Skip other details including permanent urls, doi, citation information. The most widely used catalysts for olefin ring closing metathesis are the grubbsruthenium alkyliidenes. Challenges and implications for sustainable synthesis. The first broadly applicable set of protocols for efficient z.
While relatively high activities were observed when the neutral form of the catalyst was employed, the reaction rates were attenuated upon in situ, potentiostatic reduction. The interconversion process was found to be reversible and used to modulate a series of ring closing metathesis and ring opening metathesis polymerization reactions. Supported catalysts useful in ringclosing metathesis. Synthesis of macrocyclic natural products by catalyst. Olefin ring closing metathesis rcm 8 although all catalytic systems are in principle reversible, the ring closing metathesis is driven to the right though escape of ethene gas formed in the metathesis reaction. The yield, rate and mode of metathesis are sensitive to simple olefin and nitrogen substitution. A strategy for the synthesis of polycyclic aromatic hydrocarbons pahs by the ringclosing olefin metathesis rcm of pendant olefins on a phenylene backbone has been developed. Propylene carbonate was found a suitable solvent for the ruthenium catalyzed ring closing and cross metathesis transformations of a variety of substrates including renewable fatty esters. Pdf olefin cross metathesis and ring closing metathesis. Sce, and was successfully reduced and then oxidized with high fidelity using chemical reagents. Ringclosing metathesis, or rcm, is a widely used variation of olefin metathesis in organic.
Flask tethered ring closing metathesiselectrocyclic. Ringclosing metathesis synthesis of medium and large. Applications of olefin metathesis in organic synthesis. The h6 in these molecules may be with the relative stereoposition of. A major cmacrolide was found during analysis of the frass of the storage beetle oryzaephilus surinamensis to be 9z,12z,15roctadeca9,12dien15olide 10, cucujolide xi. Olefin cross metathesis and ringclosing metathesis in. Synthesis of substituted phenols by using the ringclosing metathesisisoaromatization approach. Ringclosing metathesis has become an essential tool for cc bond formation as demonstrated by the profound impact on total synthesis in recent years. Recent advances in the stereoselective total synthesis of.
Ring closing metathesis rcm the ringclosing metathesis rcm allows synthesis of 5 up to 30membered cyclic alkenes. Ring closing metathesis an overview sciencedirect topics. After a double exposure of the sequence to ring closing metathesis conditions. View enhanced pdf access article on wiley online library html view download pdf for offline viewing. Rcm ringclosing metathesis rom ringopening metathesis romp ringopening metathesis polymerization admet acyclic diene metathesis polymerization. Pdf tandem ringclosing metathesis reaction with a ruthenium. He is currently a fourth year doctoral student working with prof. Catalytic ringclosing metathesis rcm is a widely used method for the synthesis of large unsaturated rings1,2. Sorry, we are unable to provide the full text but you may find it at the following locations. Ringclosing metathesis strategy to pheterocycles sciencedirect. Catalyst 5 promotes ringclosing metathesis rcm and the efficient formation of various trisubstituted olefins at ambient temperature in high yield within 2 h. Recent applications of ringrearrangement metathesis in. Closing metathesis synthetic routes to carbocyclic aromatic compounds using ring. Metathesis university of nairobi personal websites.
It describes opportunities and challenges associated with different ring sizes and functional groups, and experimental parameters that can be modulated to improve. Synthesis of mediumsized and macrocyclic rings by ring closing metathesis rcm reactions of dienes. School of chemistry, university of the witwatersrand, johannesburg, south africa. The ring closing metathesis rcm reaction has become a standard in olefin metathesis chemistry. Industrial applications of the olefin metathesis reaction known until 1997 have been described elsewhere, including processes that have not been commercialized and processes that are no longer commercial. This document was downloaded for personal use only. While the catalyst facilitated a range of ringclosing metathesis rcm reactions in its neutral state, its activity was inhibited upon the introduction of a suitable reducing reagent. In recent years, the olefin metathesis has advanced in a widely applicable synthetic method 9 with the development of stable transition metal based catalysts and more particularly, the ring closing olefin metathesis rcm guided synthetic protocol continues to yield spectacular success during the natural product synthesis.
Similarly, ringclosing metathesis offers the ability to tune polymer macrostructure and microstructure to similar effect. Rcm ringclosing metathesis rom ringopening metathesis romp ringopening metathesis polymerization admet acyclic diene metathesis polymerization cm crossmetathesis dr. Nonproductive events in ringclosing metathesis using. Because of the relative simplicity of olefin metathesis, it often creates fewer undesired byproducts and hazardous wastes than alternative organic reactions. Ring closing metathesis reaction screening kit materials. Identification of a grain beetle macrolide pheromone and. Olefin metathesis opens up new industrial routes to important petrochemicals, oleochemicals, polymers, and specialty chemicals. Diastereoselective ring closing metathesis an approach to.
Following the most common modern usage, in this chapter i apply the term metathesis to permutations of segments regardless of intervening material. Ringclosing metathesis synthesis of medium and large rings. Ringclosing metathesis rcm and ring opening metathesis. Chemfiles volume 9 article 6 ringclosing metathesis. Synthesis of substituted benzenes and phenols by ringclosing olefin metathesis. Kazuhiro yoshida, hidetoshi takahashi, tsuneo imamoto. A search for the topics ringclosing metathesis or ringclosing olefin metathesis in the isiweb of science, conducted in august 2012, reveals that either of these terms has been used in more than 6000 publications, which have been cited more than 173 000 times. A new methodology was developed for the ringclosing metathesis of the dienyl derivative 68 scheme 8. Rrm delivers complex frameworks that are difficult to assemble by conventional methods. Polycyclic aromatic hydrocarbons by ringclosing metathesis. Olefin metathesis is an organic reaction that entails the redistribution of fragments of alkenes olefins by the scission and regeneration of carboncarbon double bonds. The synthesis used ring closing alkyne metathesis as a key step.
It is within this context that the dimer ring closing metathesis. Temperaturedependent multicomponent solvent tms systems have been evaluated in ruthenium catalyzed olefin metathesis transformations. Recent advances in total synthesis via metathesis reactions. The rucatalysts used tolerate a variety of functional groups, but normally the molecule must have polar side chains that are able to build a template for the catalyst. Enantioselective ring expansion of prolinols and ring. To overcome the unfavorable entropic and enthalpic factors involved in the formation of the eightmembered ring with an endocyclic triple bond, a cobalt complex was previously prepared. Tandem ringclosing metathesis reaction with a ruthenium catalyst. Industrial applications of olefin metathesis springerlink. Olefin metathesis in organic synthesis wendy jen macmillan group meeting january 17, 2001 i. Olefin metathesis reaction in water and in air improved.
Key transformations include a stepwise variant of a mannichlike multicomponent assembly process, a double ringclosing metathesis sequence, and a onepot deprotection. The reaction can be driven to the right by the loss of ethylene. Knapton, daniel jason 2005 transtion metal mediated carbonheteroatom and carboncarbon bond formation. The medium ring closing metathesis kit was designed to provide the best possible chance of finding good reaction conditions to close 5, 6, and 7membered rings and is run with. Olefin metathesis transformations in thermomorphic.1547 1008 999 946 740 220 1480 945 357 972 116 916 964 1207 111 1096 1251 932 1190 310 1306 446 1348 1514 1386 20 1382 1119 1131 1152 778 718