9,10-Dihydro-9-sila-10-heteroanthracenes as new radical-based seducing agents

Abstract

9,10-Dihydro-9-silaanthracenes 1 containing a heteroatom at the 10-position have been prepared and their reducing abilities for the reduction of some organic compounds under radical conditions have been investigated. Derivatives possessing a silicon, tin, oxygen or sulfur atom at the 10-position exhibited enhanced reactivities compared with the open-chain models. Among them, 9,10-dimethyl-9,10-dihydro-9,10-disilaanthracene 1 a proved to be the most effective reagent for AIBN-initiated dehalogenation of organic halides and deoxygenation of aliphatic alcohols via O-thiocarbonyl derivatives. The rate constants for hydrogen abstraction from the Si–H moiety of these silaanthracenes 1 were determined using the neophyl rearrangement as a free radical clock in order to estimate their reactivities.