The thiolation of pentafluorobenzene with disulfides by C-H, C-F bond activation and C-S bond formation.

A metal-free thiolation reaction between pentafluorobenzene and disulfides by C-H, C-F bond activation and C-S bond formation is reported. Bisthiolated tetrafluorobenzene derivatives would be prepared in moderate to good yields from pentafluorobenzene and disulfides under mild conditions. A possible mechanism for the reaction was given.

Ruthenium-Catalyzed Enantioselective Hydrogenation of Phenanthridine Derivatives.

The first asymmetric hydrogenation of phenanthridines catalyzed by chiral cationic ruthenium diamine complexes has been developed with up to 92% ee and full conversions. The choice of the counteranion of the catalyst was found to be critical for achieving high enantioselectivity. In addition, the obtained 5,6-dihydrophenanthridine could be used as a chiral hydride donor for organocatalytic asymmetric transfer hydrogenation.

Highly Enantioselective Synthesis of Indolines: Asymmetric Hydrogenation at Ambient Temperature and Pressure with Cationic Ruthenium Diamine Catalysts.

A highly enantioselective synthesis of indolines by asymmetric hydrogenation of 1H-indoles and 3H-indoles at ambient temperature and pressure, catalyzed by chiral phosphine-free cationic ruthenium complexes, has been developed. Excellent enantio- and diastereoselectivities (up to >99 % ee, >20:1 d.r.) were obtained for a wide range of indole derivatives, including unprotected 2-substituted and 2,3-disubstituted 1H-indoles, as well as 2-alkyl- and 2-aryl-substituted 3H-indoles.

Asymmetric Borane Reduction of Prochiral Ketones Catalyzed By Helical Poly[(S)-3-vinyl-2,2'-dihydroxy-1,1'-binaphthyl].

The application of helical poly[(S)-3-vinyl-2,2'-dihydroxy-1, 1'-binaphthyl] (L*) in the asymmetric borane reduction of prochiral ketones was studied. The results showed that L* had excellent catalytic activity as well as enantioselectivity, giving up to 96% yield and up to 99% enantiomeric excess (ee) of the corresponding secondary alcohol at 25 °C. Moreover, L* can be easily recovered and reused without loss of catalytic activity.

Observation of 1,3-diketones formation in the reaction of bulky acyl chlorides with methyllithium.

The formation of 1,3-diketones was observed in the reactions of bulky acyl chlorides with methyllithium. The reaction products depend on the steric hindrance around the carbonyl group of the acyl chloride and the electronic effect of the group(s) linked to the carbonyl. When the steric hindrance around the carbonyl group of the acyl chloride is big enough, the 1,3-diketone is the only product. In the case of the moderate hindrance around the carbonyl group of the acyl chloride, a moderate yield of 1,3-diketone is obtained and some tertiary alcohol is generated. When there is no steric hindrance around the carbonyl group of the acyl chloride, the tertiary alcohol is the only product. When the steric hindrance around the carbonyl group is moderate and an electron-donating group is connected to the carbonyl of the acyl chloride, all three products--ketone, 1,3-diketone and tertiary alcohol--can be isolated from the reaction mixture after long reaction times.

Well-controlled reversible addition-fragmentation chain transfer radical polymerisation under ultraviolet radiation at ambient temperature.

Controlled reversible addition-fragmentation chain transfer radical polymerisation of methyl acrylate was carried out under long-wave (lambda > or = 365 nm) ultraviolet radiation using an acylphosphine oxide as a photoinitiator at ambient temperature; the polymerisation shows a "living" character at high conversions of polymerisation and leads to well-defined polymers with narrow polydispersities (Mw/Mn < 1.1).

Phase selectively soluble dendrimer-bound osmium complex: a highly effective and easily recyclable catalyst for olefin dihydroxylation.

A new switched biphasic catalysis system for highly effective olefin dihydroxylation has been described, in which the dendritic osmium catalyst preferred to dissolve in the non-polar organic layer and could be easily separated from the polar diol products through phase separation induced by addition of water at the end of the reaction.