Buil María L, Esteruelas Miguel A, Oñate Enrique, Picazo Nieves R
Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain.
Organometallics. 2023 Feb 9;42(4):327-338. doi: 10.1021/acs.organomet.2c00631. eCollection 2023 Feb 27.
An osmathiazole skeleton has been generated starting from the cation of the salt [OsH(OH)(≡CPh)(IPr)(PPr)]OTf (; IPr = 1,3-bis(2,6-diisopropylphenyl)imidazolylidene; OTf = CFSO) and thioacetamide; its aromaticity degree was compared with that of thiazole, and its aromatic reactivity was confirmed through a reaction with phenylacetylene. Salt reacts with the thioamide to initially afford the synthetic intermediate [OsH{κ--[NHC(CH)S]}(≡CPh)(IPr)(PPr)]OTf (). Thioamidate and alkylidyne ligands of couple in acetonitrile at 70 °C, forming a 1:1 mixture of the salts [OsH{κ--[C(Ph)NHC(CH)S]}(CHCN)(IPr)(PPr)]OTf () and [Os{κ--[CH(Ph)NHC(CH)S]}(CHCN)(IPr)]OTf (). Treatment of with potassium -butoxide produces the NH-deprotonation of its five-membered ring and gives OsH{κ--[C(Ph)NC(CH)S]}(IPr)(PPr) (). The osmathiazole ring of is slightly less aromatic than the osmathiazolium cycle of and the purely organic thiazole. However, it is more aromatic than related osmaoxazoles and osmaoxazoliums. There are significant differences in behavior between and toward phenylacetylene. In acetonitrile, the cation of loses the phosphine and adds the alkyne to afford [Os{η-κ-[CHC(Ph)C(Ph)NHC(CH)S]}(CHCN)(IPr)]OTf (), bearing a functionalized allyl ligand. In contrast, the osmathiazole ring of undergoes a vicarious nucleophilic substitution of hydride, by acetylide, via the dihydride OsH(C≡CPh){κ--[C(Ph)NC(CH)S]}(IPr)(PPr) (), which releases H to yield Os(C≡CPh){κ--[C(Ph)NC(CH)S]}(IPr)(PPr) ().
从盐[OsH(OH)(≡CPh)(IPr)(PPr)]OTf（；IPr = 1,3-双(2,6-二异丙基苯基)咪唑亚基；OTf = CFSO）的阳离子和硫代乙酰胺出发生成了一个锇噻唑骨架；将其芳香性程度与噻唑的进行了比较，并通过与苯乙炔的反应证实了其芳香反应性。盐与硫代酰胺反应最初得到合成中间体[OsH{κ--[NHC(CH)S]}(≡CPh)(IPr)(PPr)]OTf（）。的硫代氨基甲酸酯和次烷基配体在70℃的乙腈中偶联，形成盐[OsH{κ--[C(Ph)NHC(CH)S]}(CHCN)(IPr)(PPr)]OTf（）和[Os{κ--[CH(Ph)NHC(CH)S]}(CHCN)(IPr)]OTf（）的1:1混合物。用叔丁醇钾处理得到其五元环的NH去质子化产物，得到OsH{κ--[C(Ph)NC(CH)S]}(IPr)(PPr)（）。的锇噻唑环比的锇噻唑鎓环和纯有机噻唑的芳香性稍弱。然而，它比相关的锇恶唑和锇恶唑鎓更具芳香性。和对苯乙炔的行为存在显著差异。在乙腈中，的阳离子失去膦并加成炔烃，得到[Os{η-κ-[CHC(Ph)C(Ph)NHC(CH)S]}(CHCN)(IPr)]OTf（），带有一个官能化的烯丙基配体。相比之下，的锇噻唑环通过二氢化物OsH(C≡CPh){κ--[C(Ph)NC(CH)S]}(IPr)(PPr)（）发生氢化物的替代亲核取代反应，释放出H生成Os(C≡CPh){κ--[C(Ph)NC(CH)S]}(IPr)(PPr)（）。
