Unsaturated Fatty Alcohol Derivatives as a Source of Substituted Allylzirconocene

摘要

The development and use of allylic organometallic reagents has been an underlying theme of modern organic synthesis.[1] A plethora of methods currently exists for the preparation of diversely substituted allylic organometallic moieties 2 by the displacement of pre-prepared allyl reagents 1 (Scheme 1). The Z group can be a halogen (Cl, Br, I),[1e] chalcogen (O, S, Se, Te),[2] metalloid (Pb, Sn),[3] or hydrogen,[2a], [4] but also carbon (in particular tertiary carbinol).[5a]-[c] The source of the metal can be the element (M) itself (Scheme 1, Path A), which undergoes an oxidative insertion into the CZ bond. However, cross-contamination of the product with the Wurtz coupling adduct always occurs (the longer the alkyl chain R in 1, the more abundant the Wurtz coupling product). Alternatively, the source of the metal can be an organometallic derivative or a metallic salt (Scheme 1, Path B).[5d] However, all of these methods required a presynthesized allyl substrate 1 that has to be prepared independently in as few steps as possible.