Aryl Silyl Ethers\nEnable Preferential Ar−O\nbond Cleavage in Reductive Generation of Aryllithium Species

Two-electron transfer to haloarenes constitutes one of\nthe most\nreliable synthetic methodologies for the generation of aryllithiums.\nIn addition to the conventional halides, readily available aryl ethers\ncan function as potent substrates. However, it is known that the reductive\ncleavage of alkoxides is plagued by insufficient selectivity concerning\nthe cleaving bond adjacent to the ether oxygen, resulting in decreased\nreliability of these alkoxyarene substrates. In the present study,\nwe discovered that naphthalenes bearing readily installable <i>tert</i>-butyldimethylsilyl ethers undergo two-electron reduction\nwith lithium metal, resulting in lithiation at the position of the\noriginal siloxy group. DFT calculations elucidated the rationale for\nthe change in selectivity upon incorporation of the siloxy group.\nOur results underscore the practical utility of a siloxy group as\na leaving group for reductive transformations involving electron transfer.