Dehydroisomerization of 1-pentene on the diruthenium disulfido complex

Abstract In situ generated [{Ru(P(OCH 3 ) 3 ) 2 (CH 3 CN) 3 } 2 (μ-S 2 )] 4+ ( 2 ), produced by abstracting the chloride atoms from [{Ru(P(OCH 3 ) 3 ) 2 Cl} 2 (μ-Cl) 2 (μ-S 2 )] ( 1 ) with Ag + salts, reacts with 1-pentene in CH 3 CN to afford [{Ru(P(OCH 3 ) 3 ) 2 (CH 3 CN) 3 } 2 {μ-SCH 2 CH C(CH 3 )CH 2 S}] 4+ ( 4 ) via dehydroisomerization of 1-pentene, and [{Ru(P(OCH 3 ) 3 ) 2 (CH 3 CN) 3 } 2 (μ-SCH 2 CH 2 CH(CH 2 CH 3 )S)] 4+ ( 3 ), which is the reaction product from the reaction of the isolated 2 with 1-pentene.The elimination of two hydrogen atoms was confirmed by GC–MS analysis of the pentanes produced via disproportionation of two molecules of 1-pentene.In contrast, the reaction of in situ generated 2 with 1-hexene gave the cyclization product [{Ru(P(OCH 3 ) 3 ) 2 (CH 3 CN) 3 } 2 (μ-SCH 2 CH 2 CH(CH 2 CH 2 CH 3 )S)] 4+ ( 5 ) and a trace amount of the side product [{Ru(P(OCH 3 ) 3 ) 2 (CH 3 CN) 3 } 2 (μ-SSCH 2 CH CHCH 2 CH 2 CH 3 )] 3+ ( 6 ) via elimination of H + from the intermediate.Similarly, [{Ru(P(OCH 3 ) 3 ) 2 (CH 3 CN) 3 } 2 {μ-SCH 2 CH 2 CH(CH(CH 3 ) 2 )S}] 4+ ( 7 ) and [{Ru(P(OCH 3 ) 3 ) 2 (CH 3 CN) 3 } 2 {μ- SSCH 2 CH CH(CH(CH 3 ) 2 )S}] 3+ ( 8 ) were obtained from the reaction of in situ generated 2 with 4-methyl-1-pentene.