CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Centre for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
J Am Chem Soc. 2021 Mar 31;143(12):4556-4562. doi: 10.1021/jacs.1c02084. Epub 2021 Mar 18.
By using commercially available 1,4-pentadiene as a pronucleophile, a copper(I)-catalyzed regioselective asymmetric allylation of ketones is achieved. A variety of chiral tertiary alcohols bearing a terminal ()-1,3-diene unit are generated in high ()/() ratio and high enantioselectivity. Both aromatic ketones and aliphatic ketones serve as suitable substrates. Furthermore, the reactions with ()-C(alkyl)-1,4-dienes proceed in moderate yields with acceptable enantioselectivity but with low (,)/others ratio, which demonstrates the partial isomerization of ()-allylcopper(I) species to ()-allylcopper(I) species through 1,3-migration. Subsequent Heck reaction and olefin metathesis compensate for the low efficiency with C-1,4-dienes. The synthetic utility of the product is further demonstrated by a copper(I)-catalyzed regioselective borylation of the 1,3-diene group.
通过使用商业可得的 1,4-戊二烯作为亲核试剂，实现了酮的铜（I）催化区域选择性不对称烯丙基化反应。各种带有末端（）-1,3-二烯单元的手性叔醇以高（）/（）比和高对映选择性生成。芳基酮和脂肪族酮都是合适的底物。此外，（）-C（烷基）-1,4-二烯的反应以中等收率和可接受的对映选择性进行，但（，）/其他比率较低，这表明（）-烯丙基铜（I）物种通过 1,3-迁移部分异构化为（）-烯丙基铜（I）物种。随后的 Heck 反应和烯烃复分解反应弥补了 C-1,4-二烯效率低的问题。通过铜（I）催化的 1,3-二烯基团的区域选择性硼化反应，进一步证明了产物的合成实用性。
