Effect of Remote Substituents on the Torquoselectivity of 3-Silyl Cyclobutene-Derivatives Ring-Opening Reactions.

We have quantum chemically studied the structure and nature of 1-substituted 3-trimethylsilyl cyclobutenes and 2,2-disubstituted-7-trimethylsilyl bycyclo[4.2.0]octa-1(6),3-dienes comparing their reactivity to archetypal 3-substituted cyclobutene systems using density functional theory at M06-2X(PCM)/TZ2P level. We wish to understand how the ring opening reaction is affected by a substituent not directly connected to the σ Carbon-Carbon breaking bond. To this end, we have analyzed the reaction profiles considering second order perturbation energies and natural steric analysis within NBO framework.