Diastereoselective Protonation, Substitution and Addition Reactions at Pseudotetrahedral Rhenium Complexes

作者：Bock Frank; Fischer Frank; Radacki Krzysztof; Schenk Wolfdieter A^*

来源：European Journal of Inorganic Chemistry, 2010, 2010(3): 391-402.

DOI：10.1002/ejic.200901011

• Rhenium
• Chiral resolution
• N,P ligands
• S ligands

The chiral N,P ligand P(Me)(Ph)[8-(2-methylquinolinyl)] (3) was synthesized and separated into its enantiomers via diastereomeric palladium complexes. The reactions of 3 and (R(P))-3 with [CpRe(CO)(NO)(NCMe)]BF(4) (7) gave the diastereomeric complexes [CpRe(CO)(NO){P(Me)(Ph)(C(10)H(8)N)}]BF(4) [8 and (R(Re),S(P)/S(Re),S(P))-8], which, upon borohydride reduction, yielded the corresponding methyl complexes [CpRe(NO){P(Me)(Ph)(C(10)H(8)N)}(CH(3))] [9 and (R(Re),S(P)/S(Re),S(P))-9]. Treatment of 9 with HBF(4) under carefully controlled conditions gave the diastereomerically pure chelates [CpRe(NO){P(Me)(Ph)(C(10)H(8)N)}]BF(4) [(R(Re)S(P)/S(Re),R(P))-10, (R(Re),R(P)/S(Re),S(P))-10 and (R(Re),S(P))-10]. The chelate ring was opened with NaSH to produce the hydrosulfido complexes [CpRe(NO){P(Me)(Ph)(C(10)H(8)N)}(SH)] [(R(Re),S(P)/S(Re),R(P))-11, (R(Re),R(P)/S(Re),S(P))-11 and (R(Re),S(P))-11]. Each step in this sequence proceeded with retention of configuration at rhenium. Complex 11 underwent acid-promoted condensation with aldehydes to give thic aldehyde complexes [CpRe(NO){P(Me)(Ph)(C(10)H(8)N)}(S=CHR)]BF(4) (12a-d, R = Ph, Me, 4-C(6)H(4)OMe, C(6)F(5)). The addition of nucleophiles X(-) to 12a gave rhenium-coordinated alpha-chiral thiolate complexes [CpRe(NO){P(Me)(Ph)(C(10)H(8)N)}{SC(H)(Ph)(X)}] (13a-e, X = acac, PhCH(2)S, EtS, tBuS, CN) with 42-89% de. The thiolate can readily be cleaved from the rheniam complex by a methylation/chelate ring-closure strategy. The stereochemistry of the entire reaction sequence was comoborated for each step by X-ray crystallography.

• 出版日期2010-1