Diastereomeric Halfsandwich Rhenium Complexes Containing Thiolate and Thioaldehyde Ligands

Abstract

Abstract The reaction of diastereomeric methyl rhenium complexes [CpRe(NO)(NMDPP)(CH3)] (NMDPP = neomenthyl-diphenylphosphine) and [CpRe(NO)(PAMP)(CH3)] (PAMP = phenyl-2- anisyl-methylphosphine) with thiols in the presence of HBF4 gave thiolate complexes [CpRe(NO)(NMDPP)(SCH2Ph)] and [CpRe(NO)(PAMP)(SCH2R)] (R = Ph, 4-C6H4Cl, 4-C6H4OMe, 2-C4H3O, CH3, CH=CH2). Treatment of [CpRe(NO)(PAMP)(THF)]BF4 with the thiols and Na2CO3 gave the same compounds under neutral conditions. Similarly, the reaction of the chelate complex {CpRe(NO)[κP(Ph)(Me)(CH2C4H3κS)]}BF4 with thiols and NaOEt yielded the ring-opened products {CpRe(NO)[P(Ph)(Me)(CH2C4H3S)](SCH2R)} (R = Ph, 4-C6H4Cl, 4-C6H4OMe). One of the benzylic hydrogen atoms can be abstracted with [Ph3C]BF4 to give the diastereomeric thiobenzaldehyde complexes [CpRe(NO)(PAMP)(S=CHR)]BF4 (R = Ph, 4-C6H4Cl, 4-C6H4OMe) and {CpRe(NO)[P(Ph)(Me)(CH2C4H3S)](S=CHPh)}BF4. In these products, the thioformyl group is predominantly η2(C,S) coordinated to rhenium, but in a few cases the corresponding η1(S) isomers were also detected by IR and NMR spectroscopy.