Desulfurative Chlorination of Alkyl Phenyl Sulfides

The chlorination of readily available secondary and tertiary alkyl phenyl sulfides using (dichloroiodo)­benzene (PhICl₂) is reported. This mild and rapid nucleophilic chlorination is extended to sulfa-Michael derived sulfides, affording elimination-sensitive β-chloro carbonyl and nitro compounds in good yields. The chlorination of enantioenriched benzylic sulfides to the corresponding inverted chlorides proceeds with high stereospecificity, thus providing a formal entry into enantioenriched chloro-Michael adducts. A mechanism implying the formation of a dichloro-λ⁴-sulfurane intermediate is proposed

Desulfurative Chlorination of Alkyl Phenyl Sulfides

The chlorination of readily available secondary and tertiary alkyl phenyl sulfides using (dichloroiodo)­benzene (PhICl₂) is reported. This mild and rapid nucleophilic chlorination is extended to sulfa-Michael derived sulfides, affording elimination-sensitive β-chloro carbonyl and nitro compounds in good yields. The chlorination of enantioenriched benzylic sulfides to the corresponding inverted chlorides proceeds with high stereospecificity, thus providing a formal entry into enantioenriched chloro-Michael adducts. A mechanism implying the formation of a dichloro-λ⁴-sulfurane intermediate is proposed

Synthesis of Phosphorodiamidate Oligonucleotide Dimers

Azido nucleosides couple with phosphoramidites via an initial iminophosphorane, which eliminates acrylonitrile to generate the coupled dimer P(V) product. The vulnerable phosphite triester intermediate is bypassed entirely, making the methodology very suitable to solution-phase synthesis. This new coupling protocol requires no protection of the 5′-OH function and provides a new method of installing internucleosidic phosphorodiamidate bonds with near quantitative yields

Synthesis and Coordination Chemistry of a New N₄-Polydentate Class of Pyridyl-Functionalized Scorpionate Ligands: Complexes of Fe^II, Zn^II, Ni^II, V^IV, Pd^II and Use for Heterobimetallic Systems

The new potentially N4-multidentate pyridyl-functionalized scorpionates 4-((tris-2,2,2-(pyrazol-1-yl)ethoxy)methyl)pyridine (TpmPy, (1)) and 4-((tris-2,2,2-(3-phenylpyrazol-1-yl)ethoxy)methyl)pyridine (TpmPyPh, (2)) have been synthesized and their coordination behavior toward FeII, NiII, ZnII, CuII, PdII, and VIII centers has been studied. Reaction of (1) with Fe(BF4)2·6H2O yields [Fe(TpmPy)2](BF4)2 (3), that, in the solid state, shows the sandwich structure with trihapto ligand coordination via the pyrazolyl arms, and is completely low spin (LS) until 400 K. Reactions of 2 equiv of (1) or (2) with ZnII or NiII chlorides give the corresponding metal complexes with general formula [MCl2(TpmPy*)2] (M = Zn, Ni; TpmPy* = TpmPy, TpmPyPh) (4−7) where the ligand is able to coordinate through either the pyrazolyl rings (in case of [Ni(TpmPy)2]Cl2 (5)) or the pyridyl-side (for [ZnCl2(TpmPy)2] (4), [ZnCl2(TpmPyPh)2] (6) and [NiCl2(TpmPyPh)2] (7)). The reaction of (1) with VCl3 gives [VOCl2(TpmPy)] (8) that shows the N3-pyrazolyl coordination-mode. Moreover, (1) and (2) react with cis-[PdCl2(CH3CN)2] to give the disubstituted complexes [PdCl2(TpmPy)2] (9) and [PdCl2(TpmPyPh)2] (10), respectively, bearing the scorpionate coordinated via the pyridyl group. Compounds (9) and (10) react with Fe(BF4)2 to give the heterobimetallic Pd/Fe systems [PdCl2(μ-TpmPy)2Fe](BF4)2 (11) and [PdCl2(μ-TpmPyPh)2Fe2(H2O)6](BF4)4 (13), respectively. Compound (11) can also be formed from reaction of (3) with cis-[PdCl2(CH3CN)2], while reaction of (3) with Cu(NO3)2·2.5H2O generates [Fe(μ-TpmPy)2Cu(NO3)2](BF4)2 (12), confirming the multidentate ability of the new chelating ligands. The X-ray diffraction analyses of compounds (1), (3), (4), (5), and (9) are also reported