Oxygen-17 and carbon-13 nuclear magnetic resonance spectra of thiophene- and pyrrole-2-carboxaldehyde condensation products prepared from ephedrine derivatives

Natural abundance ¹⁷O nmr (acquired in acetonitrile at 70°) and ¹³C nmr (acquired in deuteriochloroform at 37°) spectroscopic data for four oxazolidines and related imino alcohols are reported: relationships of chemical shifts and ¹⁷O line widths at half-heights to structures are discussed.     

Quark model predictions on the masses of heavier vector mesons

We use the quark model considerations of Federman, Rubinstein and Talmi and the relation (m _ψ/m _ϕ)≃(m _ϒ/m _ψ)≃(m _ϒ/m _ϒ) to compute the masses of beautiful and tasty vector mesons.     

An energy-momentum tensor in gauge theories

We consider the renormalization of the twist two, dimension four gauge invariant operator O_μν⁽¹⁾ = − F_μσF_νσ − g_{μν 0}. By using the general theory of renormalization of gauge invariant operators, we find the gauge noninvariant operator O⁽²⁾ with which it mixes. We construct a finite combination of O⁽¹⁾ and O⁽²⁾ and show that it is an acceptable energy momentum tensor for gauge theories. We compare our energy momentum tensor with that constructed by Freedman, Muzinich, and Weinberg.     

SbCl3‐Al2O3–Catalyzed,Solvent‐Free,One‐Pot Synthesis of Benzo[b]1,4‐diazepines

This article explores the use of antimony(III) chloride adsorbed on neutral alumina as an efficient catalyst for the one‐pot synthesis of benzo[b]1,4‐diazepines (83–94%) under solvent‐free conditions. The process is easy, efficient, ecofriendly, and economical.     

Mechanistic approach for expeditious and solvent-free synthesis of α-hydroxy phosphonates using potassium phosphate as catalyst

An extremely simple, high yielding, highly rapid and solvent-free protocol has been described for hydrophosphylation of aldehydes using potassium phosphate as catalyst. Easy commercial availability of the reusable catalyst, operational simplicity at ambient temperature and avoidance of conventional work-up as well as purification procedure makes this solvent-free protocol a near-ideal synthesis.     

An efficient regioselective reaction of indole with 2H-chromenes for the synthesis of new 4H-chromenes in environmentally benign media

An efficient regioselective, catalyst free, and green protocol has been developed for the synthesis of a novel class of 4H-chromene scaffolds at room temperature in ionic liquid. The method is general and applicable for a series of 2H-chromenes as well as indole derivatives.     

Total synthesis of agomelatine via Friedel–Crafts acylation followed by Willgerodt–Kindler reaction

Total synthesis of antidepressant drug, agomelatine is reported. Regio selective Friedel–Crafts acylation followed by Willgerodt–Kindler reactions is used as the key steps for the synthesis of agomelatine.     

Copper‐Catalyzed Oxidative Dimerizations of 3‐N‐Hydroxy‐aminoprop‐1‐enes to form 1,4‐Dihydroxy‐2,3‐diaminocyclohexanes with C2 Symmetry

This work describes the one‐step construction of complex and important molecular frameworks through copper‐catalyzed oxidations of cheap tertiary amines. Copper‐catalyzed aerobic oxidations of N‐hydroxyaminopropenes to form C₂‐symmetric N‐ and O‐functionalized cyclohexanes are described. Such catalytic oxidations proceed with remarkable stereocontrol and high efficiency. Reductive cleavage of the two N? O bonds of these products delivers 1,4‐dihydroxy‐2,3‐diaminocyclohexanes, which are important skeletons of several bioactive molecules.