Zinc Tetrafluoroborate-Mediated Ring Expansion of -Aziridine-2-carboxylates to -2-Iminothiazolidines and -Thiazolidine-2-iminium Tetrafluoroborates and Evaluation of Antimicrobial Activity.

-2-iminothiazolidines and -thiazolidine-2-iminium tetrafluoroborates were successfully produced from --alkyl aziridine-2-carboxylates and phenyl/alkyl isothiocyanates mediated by zinc tetrafluoroborate in refluxing DCE. Reactions were performed via a complete regio- and stereoselective process to give the title iminothiazolidines and -thiazolidine-2-iminium salts in moderate to good yields (35 to 82%) with a wide substrate scope. In addition, the antibacterial activity evaluation of these compounds, as well as the minimum inhibitory concentration (MIC) determination, revealed that only four -thiazolidine-2-iminium salts showed growth inhibition against .

Straightforward synthesis of various chiral pyrimidines bearing a stereogenic center adjacent to the C-2 position, including C-terminal peptide isosteres.

The present study describes an efficient access to enantioenriched pyrimidines' derivatives from readily available Boc-AA-NH and β-enaminones. This strategy allows the synthesis of a large variety of chiral pyrimidines (18 examples) with good yields from the chiral pool. In the case of peptide isosteres, this procedure proved to be highly stereoretentive and paves the way to the construction of C-terminal modified peptidomimetics as illustrated in the synthesis of two original pyrimidines containing pseudo-dipeptides.

Rotational (de)-excitation of C by collision with He at low temperature.

An appropriate estimation of the abundance of the observed C radical in the interstellar medium requires accurate radiative and collisional rate coefficients. We present the first two-dimensional potential energy surface (2D-PES) for the ground electronic state of the C(XΣ)-He(XS) van der Waals system, obtained using an explicitly correlated coupled-cluster method with single, double, and perturbative triple excitations (RCCSD(T)-F12). This PES is subsequently used in quantum close-coupling (CC) scattering calculations.

Dynamic Kinetic Resolution Processes Based on the Switchable Configurational Instability of Allenyl Copper Reagents.

The configurational instability of allenyl copper reagents is unveiled. An experimental study highlights the crucial role of Li and of the reaction temperature in the control of the configurational stability of allenyl copper reagents. A judicious choice of the reaction conditions allows efficient dynamic kinetic resolution processes and gives a one-pot access to homopropargylic alcohols or amines bearing up to four contiguous defined stereogenic centers.

An attempt to study (111) oriented NiO-like TCO thin films in terms of structural, optical properties and photocatalytic activities under strontium doping.

This work covers some physical properties of Sr-doped NiO sprayed thin films at various concentrations (0 to 4%) prepared on glass substrates. Structural properties by using X-ray diffraction (XRD) show that all films have a cubic structure with (111) orientation. The stress, estimated by adjusting the XRD diffraction peaks increases with the doping concentration.

Collisional excitation of interstellar CCN(XΠ) induced by He.

The CCN radical has been recently detected in the interstellar medium. Accurate modeling of its abundance in such media requires one to model its excitation by both radiation and collisions. Here, we report the first quantum mechanical close-coupling study of CCN-He collisions.

Cold collisions of SH with He: Potential energy surface and rate coefficients.

Collisional energy transfer under cold conditions is of great importance from the fundamental and applicative point of view. Here, we investigate low temperature collisions of the SH anion with He. We have generated a three-dimensional potential energy surface (PES) for the SH(XΣ)-He(S) van der Waals complex.

Rotational Excitation of the CP(ΧΣ) Open Shell Molecule Due to Collision with He(S).

Phosphorus bearing molecules have been discovered in the circumstellar and interstellar media. Modeling their abundance accurately requires computations of rate coefficients induced by collision with He and H (i.e.

Rotationally inelastic dynamics of LiH (X(1)Σ(+), v = 0) in collisions with Ar: State-to-state inelastic rotational rate coefficients.

A theoretical study of rotational collision of LiH(X(1)Σ(+),v = 0, J) with Ar has been carried out. The ab initio potential energy surface (PES) describing the interaction between the Ar atom and the rotating LiH molecule has been calculated very accurately and already discussed in our previous work [Computational and Theoretical Chemistry 993 (2012) 20-25]. This PES is employed to evaluate the de-excitation cross sections.