Isomerization ruthenium-mediated

CEJ1358> and the ruthenium mediated isomerization of double bonds (cf. Scheme 89, Section 8.11.7) <2007TL137> are recent examples of transition metal catalyzed manipulations at the side chain carbon atoms of 1,3-heterocycles. A novel side-chain addition reaction of aldehydes to 6-alkylidene-l,3-dioxin-4-ones was used for the construction of intermediates of lophotoxin <2006CJC1226>. An acid-catalyzed intramolecular cycloaddition of a hydroxy group to an alkene has been effected by the presence of an adjacent 1,3-dithiane moiety <2006TL4549>. 

A conceptually neat ruthenium-mediated isomerization and ring-closing metathesis was used in the synthesis of the l/f-2-benzazepine derivative 210 in moderate yield from 207 via 208 and 209 (Scheme 27) <2003SL1859>. 

Highly substituted benzofurans have been synthesized from their corresponding substituted l-allyl-2-allyloxy-benzenes using a ruthenium-mediated C- and 0-allyl isomerization followed by RGM (Scheme 84) <2005T7746>. 

Ruthenium complexes mediate the hydroamination of ethylene with pyridine.589 The reaction, however, is not catalytic, because of strong complexation of the amine to metal sites. Iridium complexes with chiral diphosphine ligands and a small amount of fluoride cocatalyst are effective in inducing asymmetric alkene hydroamination reaction of norbomene with aniline [the best enantiomeric excess (ee) values exceed 90%].590 Strained methylenecyclopropanes react with ring opening to yield isomeric allylic enamines 591... 

Clauson-Kaas) are perhaps the most utilized methods for the de novo synthesis of pyrroles. Recent advances include the following novel approaches to 1,4-diketones Stetter addition of aldehydes to chalcones <07SC1109> ruthenium-catalyzed isomerization of 1,4-alkynediols <07TL5115> and Zn/iodine-mediated dimerization of a-bromoketones <07TL7215>. 

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