Ruthenium complexes of nitrogen- and sulfur-containing heterocycles

In the United States conventional crude petroleum reserves were depleted by 21.3% between 1978 and 1991, and is reflected by the fact that the crude oil pool has gotten heavier. Heavier crudes are associated with higher boiling point hydrocarbon fractions as well as high levels of sulfur, nitrogen, and metal constituents. The heteroatoms and metals present in the crudes poison the cracking and reforming catalysts used in petroleum upgrading. Also, combustion of heteroatoms presents environmental problems due to the formation of SO{dollar}sb{lcub}rm x{rcub}{dollar} and NO{dollar}sb{lcub}rm x{rcub}{dollar} which contribute to acid rain production. Our interest in these processes/problems has resulted in studies on interactions of heterocycles with Ru metal centers and the subsequent reactivities of these complexes.; The sandwich complexes ((C{dollar}rmsb6Mesb6)Ru(2{dollar}-{dollar}rm RCsb4Hsb3S)rbrack(OTf)sb2{dollar} are prepared by reaction of {dollar}rm (Csb6Mesb6)Ru(OTf)sb2{dollar} and 2-RC{dollar}rmsb4Hsb3S.{dollar} These species react with (S)-({dollar}-{dollar})-{dollar}alpha{dollar}-methylbenzylamine to give a 1:1 mixture of diastereomeric iminium thiolato derivatives. Isolation of the less polar diastereomer by chromatography followed by protonolysis regenerates optically pure {dollar}pi{dollar}-complexes. {dollar}pi{dollar}-Complexes of 2-substituted functionalized thiophenes, 2-{dollar}rm RCsb4Hsb3S,{dollar} have been prepared where R = HOCH{dollar}sb2,{dollar} HOCH{dollar}rmsb2CHsb2, tBocNHCHsb2, and NHsb3sp+CHsb2.{dollar} The {dollar}pi{dollar}-complexed aminomethylthiophenes are interesting because they undergo intermolecular nucleophilic addition upon treatment with base to afford oligomeric species.; Solutions of {dollar}rm(Csb6Mesb6)Ru(etasp4{dollar}-{dollar}rm Csb4Mesb4S){dollar} when treated with {dollar}rmlbrack(Csb5Hsb5)Ru(MeCN)sb3rbrack PFsb6{dollar} afford a species in which a carbon-sulfur bond is broken and the thiophene is simultaneously coordinated in an {dollar}rmetasp3{dollar}- and {dollar}etasp4{dollar}-manner to the {dollar}rm (Csb6Mesb6){dollar}Ru and {dollar}rm (Csb5Hsb5){dollar}Ru units, respectively. Crystallographic and spectroscopic data show that the complex, {dollar}rmlbrack(Csb5Hsb5)Ru(etasp4:etasp3{dollar}-{dollar}rm Csb4Mesb4S)Ru{dollar}-{dollar}rm (Csb6Mesb6)rbracksp+{dollar} is asymmetric.; Treatment of (cymene)Ru{dollar}sp2sp+{dollar} with Ni(OEP) gives a complex in which the Ru(II) center is {dollar}pi{dollar}-bound to a pyrrolide unit on the periphery of the metalloporphyrin, ((cymene)Ru-{dollar}rm{lcub}Ni(OEP{rcub}rbracksp{lcub}2+{rcub}.{dollar} In contrast to the behavior of the Ru-Ni complex, protonolysis of ((cymene)Ru{dollar}rm{lcub}Zn(OEP)OTf{rcub}rbrack{dollar}OTf results in the removal of Zn(Il) to give {dollar}rmlbrack(cymene)Ru{dollar}-{dollar}rm{lcub}(Hsb{lcub}x{rcub}(OEP){rcub}rbracksp{lcub}n+{rcub}{dollar} which was detected spectroscopically.