The quantum-chemical calculations on the conformational properties of 2-flouro-2-oxo- 1,3,2-dioxaphosphorinane (1), 2-choloro-2-oxo-1,3,2-dioxaphosphorinane (2) and 2-bromo- 2-oxo-1,3,2-dioxaphosphorinane (3) have been investigated by means of ab initio molecular orbital (HF/6-311+G**) and hybrid density functional theory (B3LYP/6-311+G**) based methods and Natural Bond Orbital (NBO) interpreta...

The high facioselectivity in the epoxidation of 4-deoxypentenosides (4-DPs) by dimethyldioxirane (DMDO) correlates with a stereoelectronic bias in the 4-DPs' ground-state conformations, as elucidated by polarized-pi frontier molecular orbital (PPFMO) analysis.

The stereochemical course of the oxidation of chiral oxazolidinone-substituted enecarbamates has been studied for singlet oxygen ((1)O(2)), dimethyldioxirane (DMD), and m-chloroperbenzoic acid (mCPBA) by examining of the special structural and stereoelectronic features of the enecarbamates. Valuable mechanistic insight into these selective oxidations is gained. Whereas the R(1) substituent on t...

Different strategies are employed in designing strong and selective anion receptors but stereoelectronic effects have been largely ignored. In this work, the stereo configuration of a non-interacting ether is found to have a large impact of more than two orders of magnitude on the binding of a rigid diol with tetrabutylammonium chloride in acetonitrile-d3. A favorable carbon-oxygen dipole and a...

Lewis acid mediated substitution reactions using [D]triethylsilane as a nucleophile at the anomeric center of the four pentofuranoses, ribose, arabinose, xylose, and lyxose, all proceed with good to excellent stereoselectivity to provide the 1,2-cis adducts. To unravel the stereoelectronic effects underlying the striking stereoselectivity in these reactions we have mapped the energy landscapes ...

The potential energy surface of the rearrangement of 3-vinylmethylenecyclobutane to 4-methylenecyclohexene has been studied computationally using density functional theory (B3LYP) and complete active space ab initio methods (CASSCF and CASPT2). The parent reaction is nonconcerted and occurs through several parallel diradical pathways. Transition structures and diradical intermediates are highly...

Stable and easy-to-handle zwitterions containing carbanion and pyridinium moieties were synthesized, and their structural studies by both X-ray crystallography and theoretical methods revealed the stereoelectronic effect in the zwitterionic 'C(-)-C-N(+)' system.

in this research, we report the results of dft calculations using xc-hybrid functional, b3lyp and employ nbo interpretation to investigate the stereoelectronic effects. electrostatic and steric impacts on the conformational properties of 1,2-difluorodiazene (1), 1,2-dichlorodiazene (2) and 1,2-dibromodiazene (3) are also studied. factors determining the thermodynamically stable molecular struct...