Metathesis hydrogenation

A one-pot cross-metathesis/hydrogenation/cyclization protocol allows for the synthesis of 6-disubstituted tetrahy-dropyran-2-ones 1001 from homoallylic alcohols 1000 and acrylic acid (Equation 393, Table 47) <20030L459>. This methodology is invaluable during the total synthesis of (—)-centrolobine <2004TL6603>. 

Scheme 2.26 Tandem metathesis/hydrogen transfer/hydrogenation sequence.

Grubbs reported tandem olefin metathesis/hydrogenation as a means to make satnrated cyclic prodncts and a one-pot RCM/transfer dehydrogenation/hydrogenation ronte to (R)-(-)-Mnscone utilizing (4a) (Scheme 19). Snapper and coworkers took advantage of the isomerization side reaction... 

Cossy et al. demonstrated that, in the presence of the ruthenium catalyst 10 and Pt02, the tandem cross-metathesis—hydrogenation—cyclization reactions of the alkenol 19 with acrylic acid 20 or acrolein 21 under H2 atmosphere gave the lactone 22 or lactol 23, respectively (Scheme 8).89 The ruthenium catalyst 10 and Pt02 are compatible under the reaction conditions. 

Tandem Cross-Metathesis/Hydrogenation Route to Lactones... 

Ru-catalyzed cross-metathesis, hydrogenation, and subsequent ring closure has been successfully combined into a one-pot tandem process for lactone synthesis. Importantly, compatibility between the catalytic systems is crucial to success. By employing the second generation Grubbs-Hoveyda catalyst in addition to Pt02, y- 6-lactones... 

Scheme 2.66 Tandem cross-metathesis/hydrogenation route to lactones [124].

Lehman, S.E., Wagener, K.B., Baugh, L.S. et al. (2007) Linear copolymers of ethylene and polar vinyl monomers via olefin metathesis-hydrogenation synthesis, characterization, and comparison to branched analogues. Macromolecules, 40,2643-2656. 

Hess GD, Hampel F, Gladysz JA (2007) Octahedral gyroscope-like molecules with m(CO)3(X) rotaUns encased in three-spoked diphosphine stators syntheses by alkene metathesis/hydrogenation sequences, structures, dynamic properties, and reactivities. Oiganometallics 26 5129-5131... 

Olefin-CO coploymers Olefin p-complexes Olefin Fibers Olefin hydroformylation Olefin hydrogenation Olefimc alcohols Olefin isomerization Olefin metathesis Olefin oligomers Olefin oxides... 

Cyclic Polyolefins (GPO) and Gycloolefin Copolymers (GOG). Japanese and European companies are developing amorphous cycHc polyolefins as substrate materials for optical data storage (213—217). The materials are based on dicyclopentadiene and/or tetracyclododecene (10), where R = H, alkyl, or COOCH. Products are formed by Ziegler-Natta polymerization with addition of ethylene or propylene (11) or so-called metathesis polymerization and hydrogenation (12), (101,216). These products may stiU contain about 10% of the dicycHc stmcture (216). 

Crotonaldehyde, hydrogenation of, 43-48 Cubane, isomerization of, 148 Cyclic dienes, metathesis of, 135 Cyclic polyenes, metathesis of, 135 Cycloalkenes, metathesis of, 134-136 kinetic model, 164 ring-opening polymerization, 143 stereoselectivity, 158-160 transalkylation, 142-144 transalkylidenation, 142-144 Cyclobutane configuration, 147 geometry of, 145, 146 Cyclobutene, metathesis of, 135 1,5,9-Cyclododecatriene, metathesis of, 135... 

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