DFT Studies on the Stereoselectivity of α-Silyloxy Diazoalkane Cycloadditions
Matthew J O'Connor1, Huaqing Liu2, Daesung Lee3
1Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago 60607, IL, USA. moconn26@uic.edu.
Abstract:
The intramolecular [3+2] cycloaddition (32CA) of alkene-tethered α-silyloxydiazoalkanes provides variable stereoselectivity in generating bicyclic pyrazolines where the silyloxy group is either syn or anti to the newly formed pyrazoline ring. To elucidate the origin of the stereoselectivity, density functional theory (DFT) calculations were carried out for the energy of each transition state structure (TSs) and product. Steric effects were identified as the major determining factors in the diastereoselectivity of the 32CA reaction with regards to substrate structure (cyclic or acyclic α-silyloxydiazoalkanes).
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