Highly Regioselective Rhodium-Catalysed Hydroformylation of Unsaturated Esters: The First Practical Method for Quaternary Selective Carbonylation
作者:Matthew L. Clarke、Geoffrey J. Roff
DOI:10.1002/chem.200600914
日期:2006.10.25
chemoselectivity. Hydroformylation of a range 1,1-di- and 1,1,2-trisubstituted unsaturated esters yields quaternary aldehydes that are forbidden products according to Keulemans Rule. The aldehydes can be reductively aminated with molecular hydrogen to give beta-amino acid esters in high yield. The overall green chemical process involves converting terminal alkynes into unusual beta-amino acid esters with only
当在环境温度(15-50摄氏度)和压力超过30 bar的条件下使用高反应性,配体改性的铑催化剂时,可以实现不饱和酯的高度区域选择性加氢甲酰化。就反应速率,区域和化学选择性而言,使用1,3,5,7-四甲基-2,4,8-三氧杂-6-磷酸金刚烷比其他常用的膦具有明显的优势。一系列1,1-二-和1,1,2-三取代的不饱和酯的加氢甲酰化反应生成季醛,根据Keulemans规则,该醛是禁止的产物。醛可以用分子氢还原胺化,以高产率得到β-氨基酸酯。整个绿色化学过程包括仅将生成的水作为基本副产物,将末端炔烃转化为不寻常的β-氨基酸酯。