The regioselectivity of the conjugate nucleophilic addition amines to vicinal di-acceptor-substituted alkenes has been studied. A set results obtained with standard primary and secondary gives some clues on relative acceptor character classical electron-withdrawing groups (EWG). We have shown in that computed inverse local nucleophilicity index can be used predict attack.

We have presented a study on structural conformation of yohimbine hydrochloride using density functional theory (DFT) method. A short description about the surface morphology with scanning electron microscopy imaging has been included. Correlation between different thermodynamic properties with variation in the temperature has been given. The global and local chemical reactivity descriptors hav...

Pd(MeCN)2Cl2 enables the α-stereoselective catalytic synthesis of 2,3-unsaturated O-glycosides from O(3)-acylated glycals without the requirement for additives to preactivate either donor or nucleophile. Mechanistic studies suggest that, unlike traditional (η3-allyl)palladium-mediated processes, the reaction proceeds via an alkoxy-palladium intermediate that increases the proton acidity and oxy...

A series of 1-arylallyl alcohols were prepared and its OH stretching frequencies measured in 20 different non-HBD solvents at room temperature. It is noticed that the observed stretching bands were highly sensitive to the nature of the solvents. Multiple parameter equations were applied to investigate the solvent effects on the O-H stretching frequency. The most significant solvent parameters w...

An efficient methodology taking advantage of the excellent nucleophilicity of aminoquinone to assemble the azaanthraquinone framework was developed via an iodine-induced 6-endo-dig electrophilic cyclization. Therefore, starting from N-propargylaminoquinones, various 3-iodo-1-azaanthraquinones were obtained in yields ranging from 45% to 90%. The metal-free protocol features facile installation o...

Palladium(II) in combination with a monodentate phosphine ligand enables the unprecedented direct and α-stereoselective catalytic synthesis of deoxyglycosides from glycals. Initial mechanistic studies suggest that in the presence of N-phenyl-2-(di-tert-butylphosphino)pyrrole as the ligand, the reaction proceeds via an alkoxy palladium intermediate that increases the proton acidity and oxygen nu...

A remarkable α-effect of silicon has been discovered that results in soft nucleophilicity at the Cγ of 3,3-bis(silyl) allyloxy lithium 1. The addition of 1 to α,β-unsaturated carbonyl compounds, including enals, proceeds in a 1,4- over 1,2-manner with medium to good regioselectivity, whereas the parent allyloxy lithium 4 undergoes complete 1,2-addition. The results from DFT calculations of HMPA...

A highly selective and convenient method for the synthesis of pyrophosphopeptides in solution is reported. The remarkable compatibility with functional groups (alcohol, thiol, amine, carboxylic acid) in the peptide substrates suggests that the intrinsic nucleophilicity of the phosphoserine residue is much higher than previously appreciated. Because the methodology operates in polar solvents, in...

Based on a preactivation protocol with (p-Tol)2SO/Tf2O, a practical, straightforward, and high-yielding synthesis of α-sialyl C-glycosides was accomplished by coupling N-acetyl-5-N,4-O-oxazolidione protected thiosialoside with various trimethylsilyl enol ethers and allyltrimethylsilanes. High yields and excellent α-selectivities were obtained for the strong π-nucleophiles with large nucleophili...