Radhey S. Srivastava

Cu(I)-catalyzed allylic amination of olefins

Abstract The copper(I) complex [Cu(CH3CN)4]PF6 catalyzes the allylic amination of alkenes by aryl hydroxylamine in fair to moderate yields. Unsymmetrical alkenes react with high regioselectivity with N-functionalization occuring at the less substituted vinylic carbon. Trapping experiments indicate that free PhNO is not an intermediate in these reactions.

Photoassisted, iron-catalyzed allylic amination of olefins with nitroarenes

Abstract Olefins react with nitroarenes and carbon monoxide photochemically in the presence of [Cp*Fe(CO) 2 ] 2 (Cp*=η 5 -C 5 Me 5 ) to produce N -aryl- N -allyl amines in moderate to good yields. Unsymmetrical olefins react highly regioselectively with N -functionalization at the less substituted vinylic carbon. Mechanistic probes using 2′-nitrobiphenyl, 2,3-dimethylbutadiene and nitrosobenzene suggest that neither aryl nitrenes nor nitrosoarenes are the active aminating agents in these reactions.

Molybdenum-catalysed allylic amination of alkenes by arylamine–ButOOH

Molybdenum peroxo complexes catalyse the regioselective allylic amination of alkenes by aryl amines with tert-butyl hydroperoxide as oxidant.

Tailored synthesis, spectroscopic, catalytic, and antibacterial studies of dinuclear ruthenium (II/III) chloro sulfoxide complexes with 5-nitro-o-phenanthroline as a spacer

A dinucleating spacer incorporating o-phenanthroline has been synthesized and characterized. The reaction of this spacer with ruthenium precursors resulted in formation of dinuclear complexes, [cis,fac-RuCl2(SO)3 (μ-nphen)cis,cis-RuCl2(SO)2], [trans,mer-RuCl2(SO)3 (μ-nphen)trans, cis-RuCl2(SO)2], and [X]+[trans-RuCl4(SO)(μ-nphen)mer-RuCl3(SO)]−, where SO = dimethylsulfoxide/tetramethylenesulfoxide, nphen = 5-nitro-o-phenanthroline, and X+ = [(dmso)2H]+, Na+, and [(tmso)H]+. These complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibility, FT-IR, FAB-Mass, 1H-NMR, 13C{1H}-NMR, and electronic spectroscopy. [trans,mer-RuCl2(dmso)3(μ-nphen)trans,cis-RuCl2(dmso)2] was also characterized on the basis of 1H–1H COSY NMR. The coordination of one ruthenium is through heterocyclic nitrogen of the o-phenanthroline and the second is through the oxygen of the nitrito group. Catalytic activity of these complexes has been investigated in hydrolysis of benzonitrile. All the complexes possess antibacterial activity against Escherichia coli and are compared to Chloramphenicol.

Fe-Catalyzed Direct α C–H Amination of Carbonyl Compounds

A direct Fe-catalyzed α-amination of 1,3-dicarbonyl compounds has been accomplished using arylhydroxylamines as aminating agents. This novel protocol allows convenient access to α-amino carbonyl derivatives without the need for any postreaction manipulations. This is an operationally simple procedure that works at low temperatures in shorter reaction times and produces high yields with excellent N-selectivity.

Copper-catalyzed allylic amination of olefins with nitrosoarenes

Abstract The transition metal catalyzed allylic amination of olefins are studied. A screening of catalysts known for the intermediacy of PhNO in the amination of alkene with phenylhydroxylamine reveals that the hydrated copper salt in conjugation with copper powder as reductant has the best catalytic properties using nitrosobenzene as nitrogen-fragment donor. The catalytic system has been studied for a variety of alkenes. Unsymmetrical alkenes react with high regioselectivity with N -functionalization at the less substituted vinylic carbon.

Direct Synthesis of β-Alkyl N-Aryl Aza Baylis–Hillman Adducts via Nitroso-Ene Reaction

A new approach for the direct Fe-catalyzed synthesis of β-alkyl N-aryl aza Baylis-Hillman (ABH) adducts is reported. This approach involves the formation of a C-N bond via a nitroso-ene reaction. This is a simple, fast, and best alternate method to overcome the substrate scope limitations of the ABH reaction, which converts allyl esters and carbonyl compounds to novel ABH adducts. A variety of arylhydroxylamines reacted with esters, aldehydes, ketone, and nitriles to yield the corresponding products in moderate to excellent yields.

Synthesis and crystal structures of carbonyl derivatives of chloride–tetramethylene sulfoxide–ruthenium(III) complexes: [RuCl3(TMSO)2(CO)] and [H(TMSO)2] [RuCl4(TMSO)(CO)]

Abstract The synthesis, spectroscopic characterization and crystal structure of [RuCl3(TMSO)2(CO)] (1) and [H(TMSO)2][RuCl4(TMSO)(CO)] (2) are reported. These complexes are prepared by the reaction of the precursors [mer-RuCl3(TMSO)3] and [H(TMSO)][RuCl4(TMSO)2] with carbon monoxide in the presence or absence of TMSO at ambient temperature and pressure. Complexes 1 and 2 represents the first examples of Ru(III) compounds bearing both tetramethylene sulfoxide and carbon monoxide ligands on the metal. Substitution of one of the two trans-S-bonded TMSO from the anion accompanied addition of one molecule of TMSO on the cation. Coordination of CO induces an S-to-O linkage isomerization of the TMSO ligands. The crystal of 1 is a red–orange needle, monoclinic, space group C2/c, a=26.446(2) A, b=8.8726(6) A, c=15.1093(8) A, β=107.427(4)°. The crystal of 2 is an orange needle, orthorhombic, space group Pnma, a=11.9820(9) A, b=14.1930(11) A, c=12.6500(15) A.

Synthesis, spectroscopic characterization and antibacterial sensitivity of some chloro dimethylsulfoxide/tetramethylenesulfoxide ruthenium(II) and ruthenium(III) complexes with 2-aminobenzothiazole

Synthesis and characterization of seven ruthenium(II) and ruthenium(III) complexes of sulfoxide with 2-aminobenzothiazole are reported. Three different formulations exist: [cis,cis,cis-RuCl2(SO)2(2-abtz)2] and [trans,trans,trans-RuCl2(SO)2(2-abtz)2] and [trans-RuCl4(SO)(2-abtz)] − [X]+ (where SO = dimethyl sulfoxide (dmso) or tetramethylenesulfoxide (tmso); 2-abtz = 2-aminobenzothiazole and [X]+ = [H(abtz)]+, [Na+]. These complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibility, FTIR, 1H NMR, 13C{1H} NMR and electronic spectroscopy. Some of the complexes were screened for their antibacterial activity and are found to be potent against the gram negative bacteria Escherichia coli.

Preparation and molecular structure of [(η5-C5H5)Fe(CO)2(η1-PhNO2)]BF4

Abstract The nitrobenzene complex [(η 5 -C 5 H 5 )Fe(CO) 2 (PhNO 2 )]BF 4 ( 1 ) has been prepared by the reaction of CpFe(CO) 2 I with AgBF 4 in the presence of nitrobenzene. Characterization by X-ray diffraction reveals that complex 1 ·1/2(CH 2 Cl 2 ) has a nearly planar PhNO 2 ligand coordinated in the η 1 -O mode. Reactivity studies indicate that 1 is not a primary intermediate in the allylic amination of olefins by nitroarenes which are catalyzed by [CpFe(CO) 2 ] 2 .