Search

Abstract: The reaction of [Cp∗IrCl2]2 (Cp*= η 5 −C5Me5) with the tridentate 3-thiapentane-1,5-dithiolate ligand, S(CH2CH2S−)2 (tpdt), led to the formation of [Cp∗Ir(η 3 −tpdt)] (1) in 81% isolated yield. Subsequent reactions of 1 with [Cp∗IrCl2]2 in 2:1 and 1:1 molar equiv ratios resulted in the formation of [Cp∗Ir(μ − η 2:η 3 −tpdt)Cp∗IrCl][PF6] (2) and [Cp∗Irμ − η 2:η 3 −tpdt)Cp∗IrCl][Cp∗IrCl3] (3) in 86 and 79% yields, respectively, based on 1, whereas the reactions of 1 with [(COD)IrCl]2 (COD=1,5-cyclooctadiene) in 2:1 and 1:1 molar equiv ratios resulted in the formation of the homo-bimetallic derivatives Cp∗Ir(μ − η 1:η 3 −tpdt)(COD)IrCl (4) (92% yield) and [Cp∗Ir(μ − η 2:η 3 −tpdt)(COD)Ir] [(COD)IrCl2] (5) (82% yield). Reactions between 1 and [(COD)RhCl]2, yielded the hetero-bimetallic derivatives Cp∗Ir(μ − η 1:η 3 −tpdt)(COD)RhCl (6) and [Cp∗Ir(μ − η 2:η 3 −tpdt)(COD)Rh][(COD)RhCl2] (7), in 92 and 93% yields, respectively. The reaction of 1 with methyl iodide gave mono-methylated derivative [Cp∗Ir(η3-C4H8S3Me)]I (8) (93% yield). All these compounds have been comprehensively characterized. [Copyright &y& Elsevier]

Abstract: Cyano-functionalized allylic phosphine substrates containing the ortho-metalated (R)-(1-(dimethylamino)ethyl)naphthalene as the chiral auxiliary were synthesized from bromoacetaldehyde dimethylacetal via a one-pot process. The diastereoselective hydrophosphination reactions of the cis- and trans-allylic phosphine substrates gave the cyano-functionalized chiral 1,2-bis(diphenylphosphino)ethane products with high yield and stereoselectivity. The subsequent organic transformation reactions of the cyano-substituted products chemoselectively afforded the formyl- and hydroxyl-functionalized chiral 1,2-diphosphine complexes with retention of stereochemistry. The coordination properties and absolute configurations of the novel 1,2-diphosphine complexes were established by single crystal X-ray crystallography. The optically pure 1,2-bis(diphenylphosphino)ethane ligands with cyano-, formyl- and hydroxyl-functionalities could be liberated in high yields from the corresponding dihalo palladium complexes by treatment with aqueous potassium cyanide. [Copyright &y& Elsevier]