Grignard Reagents: Alkoxide-Directed Iodine−Magnesium Exchange at sp3 Centers

Sequential addition of i-PrMgCl and BuLi to sp3 hybridized iodoalcohols triggers a facile iodine−metal exchange. Intercepting the resulting cyclic Grignard reagents with a slight excess of an electrophile leads to a diverse range of substituted alcohols. The iodine−magnesium exchange strategy is effective with 3-carbon iodoalcohols bearing alkyl substitutents on the carbinol or adjacent carbons and with the chain-extended homolog 4-iodobutan-1-ol.