Enantiomerization energy profile of methyl propargyl ether and its analogs containing S and Se atoms. A H ybrid density functional theory study and natural bond orbital in terpretation

The i nteraction between donor and acc eptor orbita ls plays an important role in mol ecular struct ures, stability and reac tivity۱ and it has bee n attracting increasing attention.۲,۳ The anom eric effect (A E) which originally den oted the pre ference of e lectronegative substituents at the anomeric center of py ranoses for the axial conformation arises as a result of stereoelectronic i nteractions.۴ The genera lized anomeric effect (GAE), is a generalization of this preference o bservable in acyclic compounds (such as dimethoxymethanes), as well as within rings.۴ In t he GAE, the stereoelect ronic effects cause a co nformational preference for a gauche arrangeme nt of the R-Y-C-X frag ment, where Y is an atom bearing at least one lone pairs of electrons, LP, and X is an elemen t more elec tronegative than C. In th is work, we havestudied the conformational properties of methyl propargyl ether (۱), methyl prop argyl thioet her (۲) and methyl pro pargyl selenoether (۳) by means of hybrid density functional theory (B۳LYP/۶-۳۱۱+G**) b ased method and natura l bond orbital (NBO) interpretation .۵,۶

کلیدواژه ها:

Gener alized anom eric effect ، ab initio ، N BO ، methyl propargyl ether