Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB-UMR 6302), BP 47870, Université de Bourgogne-Franche-Comté , 9 avenue A. Savary, Dijon 21078 Cedex, France.
J Org Chem. 2017 Nov 3;82(21):11358-11369. doi: 10.1021/acs.joc.7b01737.
A new method to link amino acid and peptide derivatives to [60]fullerene is described. It uses hydrophosphination with a secondary phosphine borane. First, the stereoselective synthesis of secondary phosphine borane amino acid derivatives was achieved by alkylation of phenylphosphine borane with γ-iodo-α-amino ester reagents under phase-transfer catalysis (PTC). Second, a sec-phosphine borane amino ester was saponified and coupled with α,γ-diamino esters to afford the corresponding dipeptide derivatives in good yields. Finally, the hydrophosphination reaction of [60]fullerene by the sec-phosphine borane compounds was performed under PTC to obtain C-amino acid or dipeptide derivatives in yields up to 80% by P-C bond formation. This addition reaction which proceeds in mild and moderate dilute conditions (0.03 M) leads to [60]fullerene derivatives as epimeric mixtures (∼1:1) due to the P-chirogenic center but without racemization of the amino acid or peptide moiety. In addition, the electrochemical behavior of a C-phosphine borane amino ester was investigated by cyclic voltammetry and spectroelectrochemistry after controlled-potential electrolysis. It showed evidence for the retro-hydrophosphination reaction into free [60]fullerene and sec-phosphine borane amino ester compound. Consequently, the synthesis of sec-phosphine borane amino acids followed by their use in hydrophosphination reactions of [60]fullerene under phase-transfer catalysis has demonstrated a great utility for the preparation of C-derivatives. Indeed, the hydrophosphination and the retro-hydrophosphination reactions of [60]fullerene/phosphine borane compounds offer a promising new strategy for the reversible immobilization of amino acid or peptide derivatives on carbon nanomaterials such as [60]fullerene.
描述了一种将氨基酸和肽衍生物连接到 [60]富勒烯的新方法。它使用次膦氢化为二级膦硼烷。首先，在相转移催化（PTC）下，通过苯基膦硼烷与γ-碘-α-氨基酯试剂的烷基化反应，实现了立体选择性合成二级膦硼烷氨基酸衍生物。其次，将 sec-膦硼烷氨基酸酯皂化并与α,γ-二氨基酯偶联，以良好的收率得到相应的二肽衍生物。最后，在 PTC 下，通过 sec-膦硼烷化合物对 [60]富勒烯进行氢膦化反应，通过 P-C 键形成，收率高达 80%，得到 C-氨基酸或二肽衍生物。该加成反应在温和且中等稀释条件（0.03 M）下进行，由于 P-手性中心的存在，导致[60]富勒烯衍生物为外消旋混合物（约 1:1），但氨基酸或肽部分没有外消旋化。此外，通过循环伏安法和控制电位电解后的光谱电化学研究了 C-膦硼烷氨基酸酯的电化学行为。它证明了向游离[60]富勒烯和 sec-膦硼烷氨基酸酯化合物的反氢膦化反应。因此，在相转移催化下，sec-膦硼烷氨基酸的合成及其在[60]富勒烯的氢膦化反应中的应用，为 C-衍生物的制备提供了一种很有实用价值的方法。事实上，[60]富勒烯/膦硼烷化合物的氢膦化和反氢膦化反应为氨基酸或肽衍生物在碳纳米材料（如[60]富勒烯）上的可逆固定化提供了一种很有前景的新策略。
