Diastereoselective Syntheses of (3<i>R*</i>,4<i>R*</i>)- and (3<i>R*</i>,4<i>S*</i>)-4-Aryl-3-methyl-4-piperidinemethanol and Fluoro Analogues
作者:Sébastien Schmitt、Richard C. D. Brown、Cécile Perrio
DOI:10.1021/jo302303h
日期:2013.2.1
stereochemistry were the alkoxymethylation of a metalloenamine generated from 4-aryl-3-methyl-1,2,3,6-tetrahydropyridine that afforded the (3R*,4S*)-form and the nucleophilic substitution of a fluoroarene with deprotonated 3-methyl-4-piperidinenitrile giving the (3R*,4R*)-isomer. The corresponding fluoromethyl analogues were subsequently obtained through the fluorination of the piperidinemethanols using DAST
由1,3-二甲基-4-哌啶酮实现了两个简明且高产的4-芳基-3-甲基-4-哌啶甲醇的非对映选择性合成。控制C3–C4相对立体化学的关键反应是由4-芳基-3-甲基-1,2,3,6-四氢吡啶生成的金属烯胺的烷氧基甲基化,提供了(3 R *,4 S *)形式并用去质子化的3-甲基-4-哌啶腈进行氟芳烃的亲核取代,得到(3R *,4 R *)-异构体。随后通过使用DAST对哌啶甲醇进行氟化来获得相应的氟甲基类似物。