Applications of NMR Spectroscopy in Organic Chemistry.

A mild oxidizing reagent for alcohols and 1,2-diols: o-iodoxybenzoic acid (IBX) in DMSO

The reduction of nitro compounds to the corresponding amines is one of the most utilized catalytic processes in the fine and bulk chemical industry. The latest development of catalysts with cheap metals like Fe, Co, Ni, and Cu has led to their tremendous achievements over the last years prompting their greater application as “standard” catalysts. In this review, we will comprehensively discuss the use of homogeneous and heterogeneous catalysts based on non-noble 3d-metals for the reduction of nitro compounds using various reductants. The different systems will be revised considering both the catalytic performances and synthetic aspects highlighting also their advantages and disadvantages.

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Reduction of Nitro Compounds Using 3d-Non-Noble Metal Catalysts

2-Iodoxybenzoic Acid (IBX): an Efficient Hypervalent Iodine Reagent

Analogs of the decapeptide GnRH which include two significantly modified amino acids at positions 5 and 6 inhibit the secretion of gonadotropins by the pituitary gland and inhibit the release of steroids by the gonads. Administration of an effective amount of such GnRH antagonists prevents ovulation of female mammalian eggs and/or the release of steroids by the gonads and may be used to treat steroid-dependent tumors. Particularly effective peptides which are soluble in water at physiologic pH and which have a low tendency to gel when administered in vivo have the following formula: Ac-β-D-2NAL-(4Cl)D-Phe-D-3PAL-Ser-Aph(Q.sub.1)(3-amino-1,2,4 triazole)-D-Aph(Q 2 )(3-amino 1,2,4-triazole)-Leu-Lys (isopropyl)-Pro-D-Ala-NH 2 , where Q 1 and Q 2 are amino acids, such as Gly, β-Ala, Ala, D-Ala, Ser, Aib, Ahx and Gab. Examples of other GnRH antagonists include Ac-β-D-2NAL-(4Cl)D-Phe-D-3PAL-Ser-Aph(Atz)-D-Aph(Ac)-Leu-Lys(isopropyl)-Pro-D-Ala-NH 2 , Ac-β-D-2NAL-(4Cl)D-Phe-D-3PAL-Ser-Aph(β-Ala)(3-amino-1,2,4 triazole)-D-Aph(β-Ala)(3-amino-1,2,4 triazole)-Leu-Lys(isopropyl)-Pro-D-Ala-NH 2 , Ac-β-D-2NAL-(4Cl)D-Phe-D-3PAL-Ser-Aph(Ac-D-Ser)-D-Aph(Ac-D-Ser)-Leu-Lys(isopropyl)-Pro-D-Ala-NH 2 , and Ac-β-D-2NAL-(4Cl)D-Phe-D-3PAL-Ser-Aph(Ac)-D-Aph(Ac)-Leu-Lys(isopropyl)-Pro-D-Ala-NH 2 .

C. Kirk Acosta

Papers

Tetrapropylammonium perruthenate as a mild and efficient oxidant for sensitive steroidal alcohols

SYNTHESIS OF cis AND trans-4-AMINOCYCLOHEXYL-D-ALANINE DERIVATIVES AND DETERMINATION OF THEIR STEREOCHEMISTRY