α-Tetrasubstituted Aldehydes through Electronic and Strain-Controlled Branch-Selective Stereoselective Hydroformylation
作者:Josephine Eshon、Floriana Foarta、Clark R. Landis、Jennifer M. Schomaker
DOI:10.1021/acs.joc.8b01431
日期:2018.9.7
high conversions and yields of tetrasubstituted aldehydes (e.g., 13:1 regioselectivity, 85% ee, and <1% hydrogenation for 1-fluoromethyl acrylate). The scope also encompasses both acyclic 1,1′-disubstituted and trisubstituted, electron-poor alkenes as well as di- and trisubstituted alkenes composed of small rings with exocyclic and endocyclic unsaturation. For example, 1-methylene-β-lactam furnished
加氢甲酰化利用二氢,一氧化碳和催化剂将烯烃转化为醛。这项工作将手性双二氮杂膦烷(BDP)和双膦酰氨基乙烷连接的铑络合物应用于各种烯烃的加氢甲酰化反应,以生产手性四取代的醛。带有吸电子取代基的1,1'-二取代丙烯酸酯在温和条件下(1摩尔%的催化剂/ BDP配体,150 psig气体,60°C)以高转化率和四取代醛(例如13:1区域选择性)收率进行加氢甲酰化,1-85%ee和小于1%的氢化反应(对于丙烯酸1-氟甲基丙烯酸酯)。该范围还涵盖无环的1,1'-二取代和三取代的贫电子烯烃,以及由具有环外和环内不饱和键的小环组成的二和三取代的烯烃。例如,1-亚甲基-β-内酰胺为四取代的醛提供了98%的选择性和高达83%的ee。值得注意的是,手性三取代双环亚甲基氮丙啶以> 50催化剂周转/小时的速率以> 99%的区域选择性和> 19:1的非对映选择性转化为四取代的醛。HRh(BDP)(CO)非催化反应的N