From Carboxytelomerization of 1,3‐Butadiene to Linear α,ω‐C10‐Diester Combinatoric Approaches for an Efficient Synthetic Route

Two novel reaction pathways were tested to synthesize the linear α,ω‐C10‐diester exclusively from three basic reagents: 1,3‐butadiene, carbon monoxide and methanol. Therefore, carboxytelomerization of 1,3‐butadiene and methanol was merged with methoxycarbonylation in two different ways to obtain highly linear C10‐diester. Through a palladium‐based and ‐assisted tandem catalytic system, 22 % yield of the desired C10‐diester was obtained without isolating the intermediates. Subsequently, the limitations of the novel assisted tandem catalytic concept were uncovered and based on that, a two‐step reaction regime was established. By optimization of the carboxytelomerization, the C9‐monoester as intermediate could be formed in nearly quantitative yields and excellent linearity. In a second reaction step, the isolated monoester was successfully converted by methoxycarbonylation into the desired linear C10‐diester in overall yields up to 84 %. A linear approach: Two novel efficient reaction pathways for the synthesis of linear C10‐diester directly based on 1,3‐butadiene, carbon monoxide and methanol by palladium‐catalysed carboxytelomerization and methoxycarbonylation are presented.