On the Constitutional Stability ofη1-Allylmetal Compounds
摘要:
Many eta(1)-allymetal species undergo a rapid haptotropic rearrangement. The stereochemical outcome of reactions of these allylmetal species with aldehydes depends on whether the haptotropic rearrangement is faster or slower than the reaction with the aldehyde. We present here a test system based on kinetic resolution, by which just this information becomes available. Thus, haptotropic rearrangement of cyclohexenyllithium, -magnesium chloride, -titanium triisopropoxide, and -titanium tetraisopropoxide, was found to be faster than addition to the aldehyde 9. Borotropic rearrangement in cyclohexenyldiethylborane was found to be slower than the addition to the aldehyde 9.
On the Constitutional Stability ofη1-Allylmetal Compounds
摘要:
Many eta(1)-allymetal species undergo a rapid haptotropic rearrangement. The stereochemical outcome of reactions of these allylmetal species with aldehydes depends on whether the haptotropic rearrangement is faster or slower than the reaction with the aldehyde. We present here a test system based on kinetic resolution, by which just this information becomes available. Thus, haptotropic rearrangement of cyclohexenyllithium, -magnesium chloride, -titanium triisopropoxide, and -titanium tetraisopropoxide, was found to be faster than addition to the aldehyde 9. Borotropic rearrangement in cyclohexenyldiethylborane was found to be slower than the addition to the aldehyde 9.