Cycloalkanes phenylpyridines

Cycloalkanes R R R H and chelating arenes ArH were oxidatively cross-conpled to Ar R R R by [RuClj(p-cymene)]2/TBHP/135°C (the reactants were the solvent) thus 2-phenylpyridine and cyclo-octane were cross-coupled cf. mech. Ch. 1. Other complexes (Ru(acac)3, [RuCl CCOD)] and RuHj(CO)(PPh3)3) also catalysed the reaction [78]. 

Scheme 35 Ruthenium(II)-catalyzed oxidative alkylation of 2-phenylpyridines with cycloalkanes...

With Ruthenium Various groups have worked on the arylation of cycloalkanes with 2-phenylpyridines using [Ru((p-cymene)Cl2)2] (10mol%) under the CDC conditions discussed in the preceding text [98]. The reaction was found to be sensitive to alkane ring size. 

A ruthenium(II)-catalysed oxidative cross-coupling of phenylpyridine substrates with cycloalkanes has been reported (Scheme 31) [22]. The proposed mechanism involves directed metalation of phenylpyridine and formation of a ruthenium alkyl species in the presence of ferf-butyl peroxide as an oxidizing reagent. The reaction required an excess of oxidizing reagent (4 equiv. with respect to phenylpyridine) as... 

Scheme 1.17 Methylation of 2-phenylpyridine with dicumyl peroxide (top) and CDC reaction between 2-arylpyridines and cycloalkanes (bottom).

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