What is the most probable role of zinc in the Barbier reaction based on the paper by Petrier and Luche? Group of answer choices It donates two electrons to the alkyl halide (one to the alkyl group and one to the halogen) and forms an intermediate that behaves like a carbanion. This organozinc intermediate can then attack the carbonyl, just like in a Grignard reaction. It probably provides a surface for the carbonyl and alkyl halide to react via a free radical type reaction. It provides a positive charge that stabilizes the product.