特異なルテニウムが触媒する"Borrowing hydrogen"のコンセプトに基づく有機反応を開発した。まず、Ru/JOSIPHOS触媒を用いて、1,2-ジオールとアミンの反応から光学活性β-アミノアルコールを最高99%収率ならびに77% eeで得ることに成功した。本反応は新規であり、その反応機構についても明らかにした。さらに、RuCl2(PPh3)3/DPEphos/K3PO4を組み合わせた触媒を用いることで、アルコールをアルキル化剤に用いるインドールの3位選択的アルキル化反応を達成した。高効率かつ広いタイプの基質に適用できる。 / Several novel ruthenium-catalyzed "borrowing hydrogen"-based organic reaction has been developed. For very first time optically active β-amino alcohols can be sinthesized directy by reaction of 1,2-diol and coressponding amine under Ru/JOSIPHOS catalysis in up to 99% yield and 77% ee. Since this reaction is very new, intensive investigation of the reaction mechanism was also carried out. Meanwhile, combination of RuCl2(PPh3)3/DPEphos/K3PO4 was found to be effective catalyst for alkylation of indole with alcohol as an alkylating reagent. This catalysis was highly reactive to give the corresponding alkylated indole in excellent yield for almost all types of indoles and alcohols substrates. / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University

The application of N-heterocyclic carbenes (NHCs) in organic and organometallic chemistry has been well-established. The utilization of Zr(NMe2)4 for transmetallation has facilitated the synthesis of CCC-NHC pincer transition metal complexes since 2005 by our group, including Fe, Co, Rh, Ir, Ni, and Pt. However, there have been no reports on the synthesis, characterization, and application of CCC-NHC pincer complexes involving Re and Mn to date. This dissertation aims to address this gap by discussing the synthesis and catalytic activities of CCC-NHC pincer Re and Mn complexes in crossed-coupling reactions. Chapter II will focus on the synthesis of the CCC-NHC pincer Re complex. The synthesis involved transmetallation with CCC-NHC pincer Zr complex using Re(CO)5Cl. The Re complex was characterized by 1H and 13C NMR spectroscopy, mass spectroscopy and its structure was determined by X-ray crystallographic methods. Catalytic activities of Re complex were demonstrated through borrowing hydrogen reactions for the crossed-coupling between ketones and primary alcohols, yielding α-alkylated ketones with water as the only by-product. The borrowing hydrogen reaction improved the economic efficiency when it did not require the good leaving group that conversed from primary alcohols. A wide range of substrates yielded yields ranging from 53% to 92%. Chapter III willdiscuss the expanded application of the Re complex, including borrowing hydrogen reactions for coupling between primary and secondary alcohols, as well as one-pot synthesis of quinolines via dehydrogenative/oxidative cyclization reactions. Control experiments support the proposed catalytic cycle of borrowing hydrogen reactions by the Re complex. In Chapter IV, the synthesis and catalytic activities of CCC-NHC pincer Mn complex are examined. The proposed structure of the Mn complex was supported by NMR spectroscopy, mass spectroscopy, and single X-ray diffraction. The Mn complex demonstrates catalytic activities through borrowing hydrogen and dehydrogenative cyclization, yielding α-alkylated ketones, 2-oxindole derivatives, and quinolines. The control experiments were set up and the proposed mechanism of Mn complex for borrowing hydrogen reaction were consistent with Re complex.

A range of novel and potent NQO1 and NQO2 inhibitors were synthesised. A series of 4-hydroxycoumarin analogues were prepared and assayed against NQO1. Furthermore, a more efficient synthetic route was developed by employing the “borrowing hydrogen” methodology. All the synthetic unsymmetrical dicoumarol analogues were novel and potent NQO1 inhibitors with IC50¬ values in the nanomolar range. The most potent analogues were non-toxic against the non-small cell lung cancer cell line, A549.The potential NQO2 inhibitors were classified in three different groups based on their core structure: 4-aminoquinolines, 7-chloro-4-aminoquinolines and 6-methoxy-4-aminoquinolines, where each group comprises of the following four subsets: the N-phenylated-, N-benzylated-, N-benzoylated- and the 4-hydrazinoquinoline analogues. Most of the quinoline analogues were found to be potent NQO2 inhibitors with IC50 values in the nanomolar range with the exception of the N-phenylated subset. The most potent analogues were toxic against the human breast adenocarcinoma cell line, MDA-MB-468.

京都大学 / 新制・課程博士 / 博士(人間・環境学) / 甲第23991号 / 人博第1043号 / 新制||人||245(附属図書館) / 2021||人博||1043(吉田南総合図書館) / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 藤田 健一, 教授 小松 直樹, 教授 津江 広人, 教授 大江 洋平 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DFAM

Ce mémoire de thèse se concentre sur le développement de réactions multicatalysées impliquant une activation iminium et un transfert d’hydrogène réversible rédox-neutre pour la synthèse de briques moléculaires complexes énantioenrichies à partir de composés 1,3-dicarbonylés et d’alcools allyliques.Une cascade réactionnelle combinant un complexe de fer et une pyrrolidine chirale a été développée pour la préparation d’alcools g-fonctionnalisés énantioenrichis par une approche impliquant économie d’étapes et d’atomes. L’efficacité de cette méthode impliquant une catalyse duale ainsi qu’une étape de rétro-Claisen a été démontré dans la synthèse de fragments clés de produits naturels. Cette méthodologie a ensuite été complétée par une étude mécanistique expérimentale aboutissant à une meilleure compréhension du mécanisme de cette transformation et conduisant également au développement d’une catalyse triple impliquant deux complexes métalliques et un organocatalyseur. Par la suite, une nouvelle approche pour la synthèse de lactones énantioenrichies de taille de cycles moyens a été mise au point. Cette stratégie de synthèse est basée sur une addition-1,4- organocatalysée énantiosélective de Michael, suivie d’une réduction chimiosélective qui engendre une fragmentation de Claisen.Enfin, grâce aux méthodologies développées au cours de cette thèse, la synthèse totale d’un produit naturel, la floribundane B, a été étudiée. / This manuscript is focus on the development of multicatalyzed reactions involving iminium activation and reversible neutral hydrogen transfer reaction for the synthesis of complexe enantioenriched building blocks from allyl alcohols and 1,3-dicarbonyls.An unprecedented cascade catalysis combining an iron catalyst and a pyrrolidine-base catalyst is developed for the preparation of g-fonctionalized enantioenriched alcohols in a formal redox-, atom- and step-economical approach. The efficiency of this method involving a dual catalysis and a retro-Claisen xas further demonstrated in the short synthesis of several key fragments of biologically active natural products or odorant molecule. This methodolgy was then incremented by a experimental mechanistic study allowing a better understanding of the mechanism of this transformation and leading to a new catalytic systeminvolving three different catalysts (iron complex, copper and organocatalyst). Then, we focused on the development of a new synthetic approach to enantioenriched medium-sized lactones. This methodology is based on a 1,4-Michael addition of cycloalkane-1,3-diones to a,b-insaturated aldehydes. Then, a key chemoselective reductively triggered Claisen fragmentation occurred to generate desired lactones in a rapid manner.Finally, thanks to our methodology developed during this thesis, the total synthesis of floribundane B was studied.

<strong>Introduction – Dearomatisation of Heteroaromatic Compounds</strong> The introduction provides a survey of dearomatisation reaction of heteroaromatics, with a particular focus on pyridines/pyridinium salts and furans. The mechanism, scope, and limitations of various approaches are covered, along with the goals of this project. <strong>Results and Discussion – Dearomatisation of Electron-Deficient Heteroaromatics</strong> This chapter initially explores the asymmetric addition of organometallic nucleophiles to pyridinium salts bearing a chiral counterion. Unfortunately, this approach ultimately proved unsuccessful, due to low observed enantioselectivities, and the low solubility of such salts. The second part of this chapter concerns the attempted asymmetric addition of dicarbonyl nucleophiles to electron-deficient furans, under conditions of chiral phase-transfer catalysts, affording bicyclic products in moderate enantioselectivity. Various alternative routes were also explored for the dearomatisation of furans and benzenoid systems. <strong>Introduction – Hydrogen Borrowing Alkylation Reactions with Alcohols</strong> The introduction surveys the range of methods available for the alkylation of various nucleophiles with alcohols under transition metal-catalysed conditions. Related methodologies are also explored, along with methods for the dehydrogenation of methanol. <strong>Results and Discussion - Rhodium-catalysed Methylation of Ketones Using Methanol</strong> This chapter describes the development of a novel ketone α-methylation using methanol. The development of reaction conditions is explored, followed by expansion of the substrate scope, including limitations of the methylation reaction. Mechanistic investigations support a methanol oxidation, aldol reaction/elimination, conjugate reduction pathway. Investigations into the role of O2 in the methylation reaction proved inconclusive. The utility of the reaction was also expanded via one-pot dialkylation reactions (work by Di Shen), Baeyer-Villiger oxidation of the products, and an attempted asymmetric transfer-hydrogenation. <strong>Results and Discussion - Interrupted Hydrogen Borrowing Reactions of Methanol</strong> This chapter looks to intercept intermediates from the α-methylation reaction. The selective methylenation of ketones is described, and a range of nucleophiles are screened for further functionalisation of ketones. Finally, a number of nucleophiles, including nitroalkanes, amines, peroxides and boronic acids are applied to one pot methylenation/conjugate addition protocols, affording complex products after two steps in one reaction vessel. <strong>Experimental</strong> Full experimental procedures and spectroscopic characterisation of compounds are provided.

Les activités catalytiques de complexes du ruthénium et de l'iridium ont été examinées dans trois thématiques. De nouvelles phosphines chirales bifonctionnelles à groupement acide et les complexes métalliques correspondants ont été préparés. Nous avons montré que le nouveau ligand (S)-Sulfo-binepine est très efficace pour l'hydrogénation énantiosélective de cétones aromatiques catalysée par le ruthénium et l'hydrogénation énantiosélective de cétiminesaromatiques en présence de catalyseurs de l'iridium. Sur la base d'études mécanistiques, un mécanisme de sphère externe a été proposé pour l'hydrogénation de cétones. Dans le cas de l'hydrogénation de cétimines, les intermédiaires-clés ont été obtenus, ce qui a permis de proposer deux chemins réactionnels compétitifs pour expliquer les effets sur l'énantiosélectivité. Les fonctionnalisations d'amines cycliques sur l'atome d'azote et les carbones en α et β de l'hétéroatome ont été réalisées grâce à des processus de transfert d'hydrogène assistés par des catalyseurs du ruthénium et l'iridium à ligand phosphinesulfonate. / In this doctoral thesis, the catalytic activities of new ruthenium and iridium complexes have been examined in three major topics. New chiral phosphine-containing acidic bifunctional ligands and correspondingmetalcomplexes have been prepared. (S)-Sulfo-binepine was shown to be a very efficient novel ligand for ruthenium-catalyzed enantioselective hydrogenation of aryl ketones and iridium-catalyzed enantioselective hydrogenation of arylketimines. Based on mechanistic studies, outer-sphere mechanism was proposed for ketone hydrogenation. For ketimine hydrogenation, the key intermediate and resting species have been obtained, allowing the proposal of two competitive reaction pathways to explain the effects on enantioselectivity. N- and(α,β)-C-functionalization of cyclic amines have been achieved via borrowing hydrogen processes assisted by ruthenium and iridium phosphinesulfonate catalysts.

遷移金属錯体を触媒とした原子効率に優れたアリルアルコール類の新規変換法の開発について検討した。アリルアルコール類のアルコールとしての性質に着目し、主に"Borrowing hydrogen"方法論に基づいた反応開発について検討した結果, 独自に調製された高度な水素移動制御を可能とするルテニウム触媒を用いることで、原子効率100%のアリルアルコール類のanti-Markovnikov型ヒドロアミノ化反応やヒドロアルコキシ化を始めとした反応の開発に成功した。 / Development of novel transform methods of allylic alcohols catalyzed by transition metal complexes was studied. In the result, development of anti-Markovnikov hydroamination and hydroalkoxylation of allylic alcohols catalyzed by uniquely prepared ruthenium catalysts, which had a advanced transfer hydrogen ability, on the basis of a character as a alcohol of allylic alcohols and "Borrowing hydrogen" methodology was achieved at 100% atom economy. / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University