Activation and Reactions of Chalcogen Ligands at Early Transition Metal Centers

（1）通过三硫代钨（PPh_4）[Cp*WS_3]与各种钌、铑配合物的反应，合成了一系列S-桥联的W-Ru、W-Rh双核配合物。并对异双金属的反应活性进行了研究。例如，我们发现双核氢化物Cp*W（m-S）_3RuH（PPh_3）_2与1当量的MeOCOCH反应生成Cp*W（μ-S）_3Ru（C（=CH_2）COOMe）（PPh_3）_2。而Cp*W（S）（μ-S）_2-Rh（PPh_3）_2与1当量MeOCOCH在THF中反应生成Cp*W（μ-S_2C_2HCOOMe）（μ-S）Rh（PPh_3）_2，其中炔被加到末端S原子和桥连S原子上。（2）在（PPh_4）[Cp*WS_3]的末端硫醚上进行了一系列烷基化反应。如与烯丙基氯或甲基烯丙基氯反应生成Cp* W（S）_2（SCH_2CR=CH_2）（R = H，Me）。发现其显示出烯丙基硫醇盐基团的有趣的流动行为。为了阐明其流动性机理，我们合成了新的配合物（PPh_4）[（EtMe_4C_5）W（O）（S）-（SCH_2CR= CH_2）]和（PPh_4）[（Me_5C_5）W（O）（S）（SeCH_2CR=CH_2）]，并分析了它们的变温~ 1H NMR谱。发现（PPh_4）[（EtMe_4C_5）W（O）（S）-（SCH_2CR=CH_2）]的烯丙基在两个S位之间迁移，而（PPh_4）（Me_5C_5）W（O）（S）（SeCH_2CR=CH_2）]的1，3-烯丙基在Se位上迁移。（3）成功地合成了带有三个不同硫族原子的半夹心钨配合物（PPh_4）[Cp*W（O）（S）（Se）]。进一步分离了（PPh_4）[Cp*W（O）（S）（SR*）]（R* =手性烷基）的非对映异构体，并与Li_2Se_2反应得到对映过量的（PPh_4）[Cp*W（O）（S）（Se）]。

( 1 ) We have synthesized a series of S-bridged W-Ru and W-Rh dinuclear complexes from the reactions of the half-sandwich tungsten trisuffido complex (PPh_4)[Cp*WS_3] and various ruthenium and rhodium complexes. And reactivity of the hetero-dimetallic has been examined. For instance, we have found that the dinuclear hydride complex Cp*W(m-S)_3RuH(PPh_3)_2 reacts with 1 equiv of MeOCOC≡CH to give Cp*W(μ-S)_3Ru(C(=CH_2)COOMe)(PPh_3)_2. On the other hand, the reaction between Cp*W(S)(μ-S)_2-Rh(PPh_3)_2 and 1 equiv of MeOCOC≡CH in THFgave rise to Cp*W(μ-S_2C_2HCOOMe)(μ-S)Rh(PPh_3)_2, where the alkyne was added to the terminal S atom and the bridging S atom.( 2 ) We carried out a series of alkylation reactions at a terminal sulfide of (PPh_4)[Cp*WS_3]. For instance, the reaction with allychloride or methallychloride produced Cp* W(S)_2(SCH_2CR=CH_2) (R = H, Me). which was found to show intresting fluxional behavior of the allylthiolate group. In order to elucidate the mechanism of the fluxionality, we have newly synthesized (PPh_4)[(EtMe_4C_5)W(O)(S)-(SCH_2CR=CH2)] and (PPh_4)[(Me_5C_5)W(O)(S) (SeCH_2CR=CH_2)], and have analyzed variable-temperature ^1H NMR spectra of these complexes. The allyl group of (PPh_4)[(EtMe_4C_5)W(O)(S)- (SCH_2CR=CH_2)] was found to migrate between the two S sites, while the 1,3-allyl shift occured at Se in the case of (PPh_4) (Me_5C_5)W(O)(S)(SeCH_2CR=CH_2)].( 3 ) We have successfully synthesized the halfsandwich tungsten complex which carries three different chalcoge atoms, (PPh_4)[Cp*W(O)(S)(Se)]. Furthermore, we were able to separate the diastereomers of (PPh_4)[Cp*W(O)(S)(SR*)] (R* = chiral alkyl group), and the subsequent reaction with Li_2Se_2 gave enatio-excess (PPh_4)[Cp*W(O)(S)(Se)].