Green and fast: Allylation of aromatic and aliphatic thiols, by using allyl alcohols as substrates, requires only minutes at ambient temperature with a Ru catalyst (see scheme). Quantitative conversion is normal and the catalyst possesses high functional-group tolerance.The allylation of aromatic and aliphatic thiols, by using allyl alcohols as substrates, requires only minutes at ambient temperature with either a Ru(IV) catalyst, [Ru(Cp*)(eta(3)-C(3)H(5))(CH(3)CN)(2)](PF(6))(2) (2; Cp*=pentamethylcyclopentadienyl) or a combination of [Ru(Cp*)(CH(3)CN)(3)](PF(6)) and camphor sulfonic acid. Quantitative conversion is normal and the catalyst possesses high functional-group tolerance. The use of [Ru(Cp*)(CH(3)CN)(3)](PF(6)) alone affords poor results. A comparison is made to the results from catalytic runs based on the use of carbonates rather than alcohols, by using 2 as the catalyst, and it is shown that the products from the alcohols are formed faster, so there is no advantage in using a carbonate substrate. The observed branched-to-linear (b/l) ratios when using substituted alcohols decrease with time suggesting that the catalysts isomerise the products. A new methodology from which one can select the desired isomeric product is proposed. DFT calculations and NMR spectroscopic measurements, by using an arene sulfonic acid as co-catalyst, suggest that eta(6)-complexes are not relevant for the catalytic system. Moreover, the DFT results indicate that 1) any eta(6)-complexes from the acids RC(6)H(4)SO(3)H result from deprotonation of the acid, 2) complexation of the thiol, via the deprotonated sulfur atom, is preferred over complexation of the O atom of the sulfonate, RC(6)H(4)SO(3) (-) and 3) a sulfonate O-atom complex will be difficult to detect.

The salts [Ru(Cp*)(CH3CN)(N,N)](PF6), 6 (N,N = bipyridine, 4,4′-dimethylbipyridine, and phenanthroline), react with allyl carbonates to afford new complexes that contain tethered ligands derived from deprotonation of one Cp* methyl group. The new Ru tetramethyl Cp complexes contain a CH2CHRCHCH2 fragment (R = H or Ph), which coordinates to the metal via the double bond. The salts 6 isomerize the branched carbonate PhCH(OCO2But)CHCH2 to the linear isomer.

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S-Alkylation O 0245Fast Ruthenium-Catalyzed Allylation of Thiols by Using Allyl Alcohols as Substrates. -Reaction of aromatic and aliphatic thiols with allyl alcohols as substrates requires only short reaction times at ambient temperature with either a Ru(IV) catalyst or a Ru/ camphor sulfonic acid system. Carbonate substrates [cf. (VI)] reveal no advantage. The ratios branched to linear, when substituted alcohols are used, decrease with increasing time suggesting that the catalysts cause isomerization. -(ZAITSEV, A. B.; CALDWELL, H. F.; PREGOSIN*, P. S.; VEIROS, L. F.; Chem. Eur. J. 15 (2009) 26, 6468-6477; Lab. Anorg. Chem., ETH Hoenggerberg, CH-8093 Zuerich, Switz.; Eng.) -Bartels 43-038