The Ugi four-component reaction (U-4CR) with N-hydroxyimides as a novel carboxylic acid isostere has been reported. This reaction provides straightforward access to α-hydrazino amides. A broad range of aldehydes, amines, isocyanides and N-hydroxyimides were employed to give products in moderate to high yields. This reaction displays N-N bond formation by cyclic imide migration in the Ugi reacti...

Sterols which have been identified in a transplantable preputial gland tumor are lanosterol, 24,25-dihydrolanosterol, 4cr-methylAs-cholestenol, A’-cholestenol, 7-dehydrocholesterol, and cholesterol (preceding paper (2)). Arranged in the above sequence, they suggest a possible pathway for the conversion of lanosterol to cholesterol. The studies presented in this report of acetate incorporation i...

A convenient base-mediated two-step synthesis of cotinine analogs and a one-pot base-free synthesis of iso-cotinine derivatives featuring an Ugi-4CR/cyclization protocol are reported. These approaches exploit the reactivity of the peptidyl position present in the Ugi adducts, allowing the facile construction of the γ-lactam core, as well as the introduction of a N-substituted methyl group into ...

Two syntheses of natural viridic acid, an unusual triply N-methylated peptide with two anthranilate units, are presented. The first one is based on peptide-coupling strategies and affords the optically active natural product in 20% overall yield over six steps. A more economical approach with only four steps leads to the similarly active racemate by utilizing a Ugi four-component reaction (Ugi-...

An alternative approach toward the simple and robust synthesis of highly substituted peptidic thiazole derivatives using Ugi-multicomponent reaction (U-MCR) is described. Thus, we introduced the enantiopure (R)-2-methyl-2-isocyano-3-(tritylthio)propanoate as a novel class of isocyanide in MCR. This bifunctional isocyanide was found to undergo mild cyclodehydration to afford thiazole containing ...

In this study, the effect of surface roughness and roughness morphology on the bond strength of WC-Co-Cr coatings has investigated. The three different surfaces morphology are use for this purpose. The first and tow samples sandblasted with alumina and silicon carbide respectively. Other sample no sandblasted before spraying process. The same WC-10Co-4Cr coating deposited on the substrates with...

Sébastien Serres,1,4 Daniel C. Anthony,2 Yanyan Jiang,2 Kerry A. Broom,1 Sandra J. Campbell,2 Damian J. Tyler,1 Sander I. van Kasteren,3 Benjamin G. Davis,3 and Nicola R. Sibson1,4 1Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom, 2Department of Pharmacology, Oxford OX1 3QT, United Kingdom, 3Chemistry Research Laboratory, University of Oxfor...