AbstractThis paper describes the Pd(II)‐catalyzed, picolinamide‐directing‐group‐aided C(sp2)−H (ortho) functionalization of racemic and enantiopure β‐phenylalanines and 3‐amino‐3‐phenylpropanols (1,3‐amino alcohols). The C(sp2)−H (ortho) functionalizations including arylation, bromination, iodination, and alkoxylation were attempted. The C(sp2)−H (ortho) arylation reactions gave biaryl or terphenyl‐type β‐phenylalanine scaffolds, halogenation and methoxylation reactions gave ortho C−H halogenated or methoxylated β‐phenylalanines. Additionally, the C−H arylation of an ortho‐methyl substituted β‐phenylalanine containing both C(sp2)−H and remote C(sp3)−H bonds was investigated. β‐Phenylalanine is an arylated β‐amino acid motif present in various natural products, bioactive molecules, and β‐peptides and it is a precursor to medicinally active compounds. Accordingly, this work contributes to the expansion of the library of unnatural β‐phenylalanine (β‐amino acid) derivatives through site‐selective C−H functionalization.
摘要 本文介绍了钯(II)催化、吡啶酰胺定向基团辅助的外消旋和对映纯 β-苯丙氨酸和 3-氨基-3-苯基丙醇(1,3-氨基醇)的 C(sp2)-H(正交)官能化。尝试了 C(sp2)-H(正交)官能化,包括芳基化、溴化、碘化和烷氧基化。通过 C(sp2)-H(正交)芳基化反应得到了双芳基或三联苯型 β-苯丙氨酸支架,通过卤化和甲氧基化反应得到了正交 C-H 卤化或甲氧基化 β-苯丙氨酸。此外,还研究了含有 C(sp2)-H 键和远端 C(sp3)-H 键的正交甲基取代的 β-苯丙氨酸的 C-H 芳基化反应。β -苯丙氨酸是一种芳基化的 β -氨基酸基团,存在于各种天然产物、生物活性分子和 β -肽中,是具有药用活性的化合物的前体。因此,这项工作有助于通过位点选择性 C-H 功能化来扩展非天然 β-苯丙氨酸(β-氨基酸)衍生物库。