Lead was found to efficiently mediate the allylation reactions of carbonyl compounds with cyclic allylic halides in the presence of stoichiometric amounts of lithium chloride and a catalytic amount of GaCl3 (20 mol %), leading to the desired homoallylic alcohols in modest to high yields with excellent diastereocontrol (>99:1 syn/anti) and good functional group tolerance. In contrast, the use of either 2-pyridinecarboxaldehyde as the carbonyl substrate or (E)-cinnamyl bromide as the allylating agent produced the corresponding product with reversed diastereoselectivity (>99:1 anti/syn).

An efficient transition metal‐free approach to achieve the selective cleavage of the α‐carbonyl C(sp3)−H bond in alkyl esters by using inexpensive, low‐toxic, and insensitive perfluoroalkyl iodide as the radical initiator has been developed. A variety of enamides, N‐heterocycles, amides, thiophenols, and phenols could be successfully incorporated into functionalized alkyl groups by intermolecular amination, thioetherification, and etherification. The distinguishing features of this CDC reaction are its broad substrate scope, synthetic simplicity, and mild reaction conditions.magnified image