Supramolecular Asymmetric Photochirogenesis with Biopolymers as Chiral Reaction Field

在这项研究中，我提出了一种不对称光化学的新策略或新的超分子光生作用的概念，即生物分子的手性信息通过手性生物分子主体与前手性客体底物的溶液相超分子相互作用以及随后产生的主-客体络合物的单分子和双分子光化学反应转移或倍增到光产物中。以修饰的环糊精、寡核苷酸、DNA、RNA和蛋白质为手性生物分子宿主的所有超分子光致化学方法都成功地以良好的光学产率产生了光学活性的光产物。因此，利用手性生物分子的超分子相互作用进行光化学不对称合成的最初想法已经被证明是一种新的光致手性方法学，并有可能推广到其他超分子体系。在这次…中获得的主要发现第一章研究了(Z)-环辛烯的超分子对映异构化反应，包括并敏化了几种具有不同生色团的α-，β-和/或γ-环糊精。基于取代基、溶剂和温度效应，详细讨论了包合物的络合行为和随后的对映异构光敏化机理。在第二章中，以相同的(Z)-环辛烯对手性(E)-异构体的对映异构化反应为模型体系，考察了双链DNA在水溶液中的敏化和对映异构体的能力。对不同序列的相应核苷、单链和双链寡核苷酸的敏化能力和对映体分化能力也进行了检测，以探讨DNA对映体分化光异构化的起源。在第三章和第四章中，我们研究了牛血清白蛋白(BSA)和人血清白蛋白(HSA)的双分子超分子不对称光环二聚反应。首先研究了AC与BSA和HSA在水溶液中的结合行为，并在不同条件下进行了超分子对映体选择性光环二聚反应，以阐明AC的结合机理和后续的光反应，从而得到光学活性的AC光环二聚体。较少

In this study, I have proposed a new strategy of asymmetric photochemistry or a new concept of "supramolecular photochirogenesis," in which the chiral information of biomolecules is transferred to or multiplied in photoproducts through the solution-phase supramolecular interaction of chiral biomolecular hosts with prochiral guest substrates and the subsequent Uni.- and bimolecular photochemical reactions of the resulting host-guest complexes. All of the examined supramolecular photochirogenic approaches, employing modified cyclodextrins, (oligo)nucleotides, DNA, RNA, and protein as chiral biomolecular hosts, were successful in creating optically active photoproducts in good optical yields. Thus, the original idea of using the supramolecular interactions of chiral biomolecules in photochemical asymmetric synthesis has been demonstrated to be useful as a novel photochirogenic methodology, and is potentially extended to the other supramolecular systems. The major findings obtained in this … More thesis may be summarized as follows.Chapter 1 is devoted to the supramolecular enantiodifferentiating photoisomerization of (Z)-cyclooctene included and sensitized by several modified α-,β-, and/or γ-cyclodextrins possessing a variety of chromophores. The inclusion complexation behavior and the subsequent enantiodifferentiating photosensitization mechanism are discussed in detail on the basis of the substituent, solvent, and temperature effects.In Chapter 2, the same enantiodifferentiating photoisomerization of (Z)-cyclooctene to the chiral (E)-isomer was employed as a model system to assess the sensitizing and enantiodifferentiating abilities of double stranded DNA in aqueous solution. The sensitizing and enantiodifferentiating abilities of the relevant nucleosides and single- and double-stranded oligonucleotides of different sequences are also examined to assess the origin of enantiodifferentiating photoisomerization by DNA. A novel supramolecular enantiodifferentiating photoisomerization system, employing oligonucleotides, and DNA, will be proposed.In Chapter 3 and 4, a novel bimolecular supramolecular asymmetric photocyclodimerization of 2-anthracenecarboxylate(AC) bound to bovine and human serum albumin (BSA, HSA) and is investigated in aqueous solutions. The binding behavior of AC to BSA and HSA in aqueous solutions is first assessed and the supramolecular enantioselective photocyclodimerization is performed under a variety of conditions in order to clarify the mechanisms of binding and the subsequent photoreactions to give the optically active photocyclodimers of AC. Less