New Bis(Imino)Pyridine Complexes Of Iron(Ii) And Iron(Iii), And Their Catalytic Activity In The Mukaiyama Aldol Reaction, Pushkar Shejwalkar, Nigam P. Rath, Eike B. Bauer
Nov 2013
New Bis(Imino)Pyridine Complexes Of Iron(Ii) And Iron(Iii), And Their Catalytic Activity In The Mukaiyama Aldol Reaction, Pushkar Shejwalkar, Nigam P. Rath, Eike B. Bauer
Nigam Rath
New iron(II) and iron(III) complexes bearing bis(imino)pyridine ligands were synthesized and successfully applied to the Mukaiyama aldol reaction. The two complexes [FeCl2 L] (L = bis(imino)pyridine ligand, 55% isolated yield) and [LFe(μCl)3FeCl3] (76%) were obtained employing FeCl2 and FeCl3 iron sources, respectively, and characterized by elemental analyses, mass spectrometry, IR spectroscopy and, one example, by X-ray diffraction. The two new iron complexes were subsequently employed as catalysts in the Mukaiyama aldol reaction after abstraction of two chlorides by AgSbF6 to obtain the aldol products in 43% to virtually quantitative yield (CH2Cl2 solvent, room temperature, 3.5 to 16 h reaction time). …
(1e,3e)-1,4-Bis(4-Methoxyphenyl)Buta1,3-Diene, Gopinathan Narayan, Nigam P. Rath, Suresh Das
Oct 2010
(1e,3e)-1,4-Bis(4-Methoxyphenyl)Buta1,3-Diene, Gopinathan Narayan, Nigam P. Rath, Suresh Das
Nigam Rath
The title compound, C18H18O2, which exhibits blue emission in the solid state, is an intermediate in the preparation of liquid crystals and polymers. The molecule is located on an inversion centre. In the crystal, molecules are arranged in a herringbone motif.
New Chiral Phosphoramidite Complexes Of Iron As Catalytic Precursors In The Oxidation Of Activated Methylene Groups, Pushkar Shejwalkar, Nigam P. Rath, Eike B. Bauer
Apr 2010
New Chiral Phosphoramidite Complexes Of Iron As Catalytic Precursors In The Oxidation Of Activated Methylene Groups, Pushkar Shejwalkar, Nigam P. Rath, Eike B. Bauer
Nigam Rath
New phosphoramidite complexes of iron were synthesized and structurally characterized. Reaction of the known chiral phosphoramidites (RO)2PNR’2 (R = binaphthyl, R’ = CH3, 1a; R = binaphthyl, R’ = benzyl, 1b) with [FeBr(Cp)(CO)2] afforded the title compounds [FeBr(Cp)(CO)(1a,b)] (4a,b) in 34 and 65 % isolated yields as mixtures of diastereomers, since both the metal and the ligand are stereogenic. Similarly, reaction of 1b with [Fe(Cp)I(CO)2] in the presence of catalytic [Fe(Cp)(CO)2]2 afforded [Fe(Cp)I(CO)(1b)] (5b) in 81% yield as a mixture of diastereomers. The molecular structures of 4a, 4b and 5 were determined, revealing a pseudo octahedral coordination geometry about the …
2-Phenyl-3-(5,6,7,7a-Tetrahydro-1h,3h-Pyrrolo[1,2-C]Oxazol-3-Ylidene)-1-Propene-1,1-Dicarbonitrile And 4-(4-Methoxyphenyl)-2,6-Bis(Methylthio)Pyridine-3-Carbonitrile, M. George, S. Das, C.V. Ashokan, N.P. Rath, M.V. George
Jul 1998
2-Phenyl-3-(5,6,7,7a-Tetrahydro-1h,3h-Pyrrolo[1,2-C]Oxazol-3-Ylidene)-1-Propene-1,1-Dicarbonitrile And 4-(4-Methoxyphenyl)-2,6-Bis(Methylthio)Pyridine-3-Carbonitrile, M. George, S. Das, C.V. Ashokan, N.P. Rath, M.V. George
Nigam Rath
The reaction of 3-aryl-2-cyano-5,5-bis(methylthio)penta-2,4-dienenitrile, (1), with (L)-(-)-2-hydroxymethylpyrrolidine, (2), gave two types of product, the normal substitution product, (3), and a pyridine derivative, (4). The structures of two representative examples, 2-phenyl-3-(5,6,7,7a-tetrahydro1H,3H-pyrrolo[1,2-c]oxazol-3-ylidene)-1-propene-1,1-dicarbonitrile, (3a), as its hemibenzene solvate, C17H14N3O.0.5C6H6, and 4-(4-methoxyphenyl)-2,6-bis(methylthio)pyridine-3-carbonitrile, (4b), C15H14N2OS2, have been unambiguously established by X-ray crystallographic analysis. The molecular packing of (4b) involves loosly held dimers with S1...S1' distances of 3.424 (1) Å.
