Study On The Cu-Catalyzed Semipinacol Rearrangement Of Cyclopropene α-Carbon Alcohol

The semi-Pinacol rearrangement(SPR)is a highly useful molecular transformation that grants access to various β-chiral ketones and aldehydes.The reaction has seen wide-spread applications in natural product syntheses.The SPR is generally triggered via four different modes:(1)epoxy ring-opening initiated rearrangement;(2)dehydration of1,2-difunctionalized alcohol-initiated rearrangement;(3)rearrangement induced by electrophilic and radical addition to double bond(with the latter often coupled with radical/polar crossover);and(4)transition metal carbenoid involved rearrangement.Of the four categories,the first three types have been well established,and the fourth type is significantly rare,and only one example in Au-catalysis is reported so far.In this thesis,the Cu(I)-catalyzed ring-opening/semi-Pinacol rearrangement of cyclopropenyl carbinols are studied.The product is formed from protonation of the allylic Cu(I)species genrated after the rearrangement.Interestingly,the ratio of the regioisomers could be arbitrarily tuned by the choice of catalyst precursor.This finding makes facile access to non-conjugated alkenyl carbonyl derivatives.