Parmi les énergies renouvelables, l’énergie solaire est la plus puissante. L’élément clé des DSSCs est le photosensibiliseur, par lequel la génération de photocourant est possible. L’autre élément important est l’électrolyte. Les liquides ioniques (Ils) sont utilisés en tant qu’électrolytes dans les DSSCs du fait de leurs propriétés chimiques: pression de vapeur basse, haute résistance thermique et chimique, polarité et phase modulables, etc. L’objectif de cette thèse est de comprendre les processus photophysiques dans les colorants dérivés d’indolines dans les solvants moléculaires (MS) et les mélanges IL/MS. L’influence du solvant sur les propriétés spectroscopiques de D131, D102, D149 and D205 est d’abord étudiée par spectroscopie stationnaire d’absorption et de fluorescence. Ensuite, la spectroscopie résolue en temps est employée pour étudier leur photophysique et sa dépendance au solvant. Ces expériences ont permis de démontrer l’influence des paramètres d'aptitude de donneur de liaison hydrogène et d'accepteur de liaison hydrogène des solvants. Le rôle majeur de la dynamique de solvatation dans la dynamique des états excités de ces colorants a été montré. Ce phénomène a été suivi dans les mélanges IL/MS en utilisant une sonde fluorescente classique, C153, et des techniques de fluorescence résolues en temps et de dynamique moléculaire. Les réponses de solvatation multi-régimes de ces mélanges sont dirigées par le renforcement de la liaison hydrogène entre la sonde et les composants des mélanges. Les résultats de cette these apportent beaucoup à la compréhension des processus photophysiques fondamentaux régissant les sensibiliseurs et les électrolytes dans les DSSCs. / Among all the renewable energy sources, solar energy is the most powerful source far ahead wind or geothermal energies. The first key component of DSSCs is the photosensitizer. It is through this component that the most important steps of photocurrent generation are possible. On the other hand, ionic liquids (ILs) have been proposed as electrolyte for DSSCs due to their peculiar properties: low vapor pressure, high thermal and chemical robustness, tunability of polarity and phase behaviour etc. The objective of this thesis was to get an understanding of the photophysics in the indoline derivated dyes in molecular solvents (MS) and in the IL/MS mixtures. Firstly, the solvent dependence of the spectroscopic properties of D131, D102, D149 and D205 was studied by the steady-state UV-Vis absorption and fluorescence spectroscopy. Then, time-resolved spectroscopy was used to elucidate their photophysics and its solvent dependence. These experiments helped to discern the influence of the hydrogen bond donor and acceptor abilities of the solvent. The solvation dynamics was shown to play a major role in the excited state dynamics of these dyes. This process in IL/MS mixtures was elucidated using the classic fluorescent probe C153 by the means of time-resolved spectroscopy and MD simulations. The complex multi-regime solvation response in these systems was shown to be shaped by the strengthening of the hydrogen bonding between the probe and the mixture components. The results of this thesis work contribute to the fundamental understanding of the photodynamics of the sensitizer and the response of the electrolyte used in the DSSCs.

Thesis advisor: X. Peter Zhang / Asymmetric C–H functionalization represents one of the central topics in modern organic chemistry, which allows for the direct installation of functional groups onto ubiquitous C–H bonds in organic molecules. Among numerous elegant strategies, transition metal-catalyzed C–H alkylation with diazo compounds represents one of the most powerful methods for C–C bond formation. Different from Fischer metallocarbene-based C–H insertion reactions, cobalt(II)-based metalloradical catalysis (MRC) is recently proven to be capable of activating acceptor/acceptor diazo compounds for radical C–H alkylation reactions via H-atom abstraction. In this dissertation, we have developed several systems by utilizing less-explored aryl and alkyl diazomethanes as new radical precursors for highly enantioselective radical C–H alkylation reactions, which permit the efficient synthesis of different optically active heterocyclic compounds. First, we have demonstrated the feasibility of using aryl aldehyde-derived sulfonylhydrazones as new radical precursors for enantioselective radical C–H alkylation to synthesis enantioenriched 2,3-dihydrobenzofuran derivatives. Notably, a general and mild way for in situ generation of diazo compounds have been identified by using 2,4,6-triisopropyl sulfonyl hydrazone as diazo precursor, which allow us to regulate the reaction temperature to achieve the high enantioselectivity for the desired radical reactions. Second, the utility of Co(II)-based MRC has been further highlighted by enantioselective indoline synthesis. Through the design and synthesis of new catalysts, the system is shown to have a broad spectrum of substrate scope, forming various 2-substituted indolines with up to 98% yield and 96% ee. A series of mechanistic studies further support the underlying stepwise radical alkylation pathway. Finally, we further expand the applicability of MRC to even more challenging diazo compounds, aliphatic diazomethanes. Starting from alkyl aldehyde-derived sulfonylhydrazones as diazo precursors, the Co(II)-based radical alkylation reactions allow for the enantioselective synthesis for common 2-substituted tetrahydrofuran structures with high yields and excellent enantioselectivities. / Thesis (PhD) — Boston College, 2019. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Les réactions multicomposants sont des réactions faisant intervenir au minimum trois composés pour la préparation d'un produit contenant la majeure partie des atomes de départ. Elles constituent l'un des procédés les plus performants en synthèse organique. En diminuant les coûts et les rejets par rapport aux réactions classiques de chimie organique, elles sont également plus économes et plus respectueuses de l'environnement. De plus, en permettant la formation rapide et efficace d'une large librairie de molécules complexes à partir de substrats simples, elles représentent un outil à forte valeur ajoutée dans le domaine pharmaceutique pour l'élaboration de chimiothèques. Face à ces enjeux, le laboratoire a développé en 2006 une réaction multicomposants de type Mannich entre des organozinciques, des amines et des aldéhydes. Cette réaction permet la synthèse efficace d'une variété importante de diarylméthylamines, dont la structure amine α,α-disubstituée est rencontrée dans de nombreux composés d'intérêt pharmacologique.A partir de ces travaux, il a été envisagé d'étendre la réaction multicomposants à la préparation de β-amino esters N-protégés. La réaction a été mise au point à partir d'un acrylate, d'une imine préformée et d'un organozincique aromatique formé in situ dans des conditions de type Barbier. Ces conditions opératoires présentent l'avantage d'éviter l'étape préliminaire de formation de l'organométallique.Par la suite, lors d'essais portant sur le développement d'une réaction à quatre composants entre un aldéhyde, un sulfonamide, un acrylate et un halogénure aromatique, nous avons observé, lorsque le manganèse est utilisé comme réducteur du bromure de cobalt, la formation majoritaire d'un diarylméthylsulfonamide résultant d'une nouvelle réaction à trois composants entre l'aldéhyde, l'amine primaire et le dérivé halogéné. Les conditions opératoires ont donc été optimisées afin de synthétiser de nombreuses diarylméthylsulfonamides.Enfin, en se basant sur la différence de réactivité des deux atomes de brome d'un composé dibromé, il a été envisagé la synthèse en deux étapes d'indolines en partant de bromure de benzyle ortho-bromé, par l'intermédiaire d'une réaction de Mannich benzylique puis une seconde étape d'amination aromatique intramoléculaire, catalysée au palladium. / Multicomponent reactions are processes in which at least three starting materials react together to form a product containing most of the starting atoms. They constitute one of the most efficient processes in synthetic organic chemistry. They are also more economical and environmentally friendly than classic organic reactions. Moreover, since they allow a straightforward access to large libraries of compounds containing the same core unit, they represent a valuable tool for pharmaceutical industries, especially for high-throughput screening. In 2006, the laboratory developed a Mannich-type multicomponent reaction between aromatic organozinc compounds, aldehydes and secondary amines allowing the efficient preparation of diarylmethylamines. These structures, and more generally the α,α-disubstituted amine core unit, are found in a large range of compounds displaying diverse pharmacological properties. On the basis of this work, it was planned to extend the reaction to other families of compounds, N-protected β-amino esters and diarylmethylsulfonamides. In the first part of this work, a range of β-amino esters have been prepared starting from in situ-generated aromatic organometal compounds (Barbier-like conditions), acrylates and preformed sulfonylimines. These conditions present the advantage to avoid the pre-formation of the organometallic compound. Thereafter, during tests pertaining to the development of a four component reaction between an aldehyde, a sulfonamide, an acrylate and an aromatic halide, it was observed the major formation of diarylmethylsulfonamide resulting from the three-component reaction between the aldehyde, the primary amine and the halide, when manganese is used as the reducer of cobalt bromide. The experimental conditions were thus optimized in order to synthesize many diarylmethylsulfonamides.Lastly, based on the difference of reactivity between benzylic and aromatic C-Br bonds, it was described the two-step synthesis of various 1,2-substituted indolines starting from ortho-brominated benzyl bromide by means of a benzylic Mannich-like reaction followed by palladium-catalyzed intramolecular amination of the aromatic ring

京都大学 / 新制・課程博士 / 博士(薬科学) / 甲第24557号 / 薬科博第174号 / 新制||薬科||19(附属図書館) / 京都大学大学院薬学研究科医薬創成情報科学専攻 / (主査)教授 大野 浩章, 教授 高須 清誠, 教授 大宮 寛久 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM

Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The initial charge transfer from dye molecules' excited states to the conduction band of a semiconductor, after absorption of visible light by the former, is critical to the performance of Dye sensitized Solar Cells (DSC). In a ZnO-based DSC sensitized by the organic indoline derivative D149, the dynamics associated with charge transfer are investigated with femtosecond transient absorption spectroscopy. The time-resolved measurement of the photo-initiated processes reveal electron transfer rates corresponding to excited state lifetimes of 100s of fs, consistent with previously measured high absorbed photon to current conversion efficiencies. The photo-electrode measured as an isolated system shows decay times of bound electrons in excited states of the dye to be ~150 fs and shows the subsequent emergence of absorption bands of the oxidized molecules. When the I-/I-3 redox couple is added to the system, these excited state lifetimes change and are found to be dependent on the cation in the electrolytic solution. Small cations like Li+ reduce the excited state lifetime to sub-100 fs, whilst larger cations like the organic tetrabutylammonium result in longer lifetimes of 240 fs. The action of the electrolyte can be observed by the reduced lifetime of the oxidized dye molecules' absorption bands. The effect of operating parameters and changes in the production protocol of the DSC on the primary charge injection are also investigated and reported on. / AFRIKAANSE OPSOMMING: Die aanvanklike ladingsoordrag vanuit kleurstofmolekules' opgewekte toestande tot in die leidingsband van 'n halfgeleier, na absorpsie van sigbare lig deur eersgenoemde, is van kritiese belang vir die uitset van halfgeleier-gebaseerde sonkragselle wat met kleurstowwe vir absorpsie verhoging, gebind is. In hierdie werk word hierdie proses en verwante fotodinamika in die geval van 'n ZnO sonkragsel gekleur met indolien D149 ondersoek d.m.v femtosekonde-tydopgelosde absorpsiespektroskopie. Hierdie metings onthul elektron-oordragstempos wat ooreenstem met lewenstye van opgewekte toestande in die orde van 100 fs. Hierdie is met voorheen-bepaalde hoë foton-tot-stroom omskakelingsdoeltreffendheid ooreenkomstig. Die foto-elektrode, as geïsoleerde sisteem beskou, toon afvalstye van gebonde elektrone in opgewekte toestande van ~150 fs, en die gevolglike opkoms van absorpsie deur geoksideerde molekules word waargeneem. As die I-/I-3 redoks oplossing tot die sisteem bygevoeg word, verander die opgewekte toestande se afvalstye en toon 'n katioon-afhanklikheid. Klein katioone soos Li+ verkort die afvalstye tot onder 100 fs, terwyl groter katioone soos die organiese tetra-butielammonium langer afvalstye (240 fs) tot gevolg het. Die werking van die elektrolitiese oplossing kan waargeneem word deur die verkorte lewenstyd van die absorpsiebande wat aan die geoksideerde molekules toegeken is. Die uitwerking van operasionele parameter asook veranderinge in die produksie protokol op die primêre ladingsoordrag word ondersoek en verslag daarop word gelewer.

The selective transformation of carbon-carbon and carbon-hydrogen bonds represents an attractive approach and rapidly developing frontier in synthesis. Benefits include step and atom economy, as well as the ubiquitous presence in organic molecules. Advances to this exciting realm of synthesis are described in this thesis with an emphasis on the development of catalytic, selective reactions under mild conditions. Additionally some applications of the methodologies are demonstrated. In Chapter 1, the first examples of inter-and intramolecular enantioselective conjugate alkenylations employing organostannanes are reported. A chiral, cationic Rh(I)-diene complex catalyzed the enantioselective conjugate addition of alkenylstannanes to benzylidene Meldrum’s acids in moderate enantiomeric ratios and yields. Notably, the cationic and anhydrous conditions required for the asymmetric alkenylation are complementary to existing protocols employing other alkenylmetals. In Chapter 2, a domino, one-pot formation of tetracyclic ketones from benzylidene Meldrum’s acids using Sc(OTf)3 via a [1,5]-hydride shift/cyclization/Friedel-Crafts acylation sequence is described. Respectable yields were obtained in accord with the ability to convert to the spiro-intermediate, and considering the formation of three new bonds: one C-H and two C-C bonds. An intriguing carbon-carbon bond cleavage was also serendipitously discovered as part of a competing reaction pathway. In Chapter 3, the pursuit of novel C-H bond transformations led to the development of non-carbonyl-stabilized rhodium carbenoid Csp3-H insertions. This methodology enabled the rapid synthesis of N-fused indolines and related complex heterocycles from N-aziridinylimines. By using a rhodium carboxamidate catalyst, competing processes were minimized and C-H insertions were found to proceed in moderate to high yields. Also disclosed is an expedient total synthesis of (±)-cryptaustoline, a dibenzopyrrocoline alkaloid, which highlights the methodology. In Chapter 4, the Lewis acid promoted substitution of Meldrum’s acid discovered during the course of the domino reaction was explored in detail. The protocol transforms unstrained quaternary and tertiary benzylic Csp3-Csp3 bonds into Csp3-X bonds (X = C, N, H) and has even shown to be advantageous with regards to synthetic utility over the use of alternative leaving groups for substitutions at quaternary benzylic centers. This reaction has a broad scope both in terms of suitable substrates and nucleophiles with good to excellent yields obtained (typically >90%).

The selective transformation of carbon-carbon and carbon-hydrogen bonds represents an attractive approach and rapidly developing frontier in synthesis. Benefits include step and atom economy, as well as the ubiquitous presence in organic molecules. Advances to this exciting realm of synthesis are described in this thesis with an emphasis on the development of catalytic, selective reactions under mild conditions. Additionally some applications of the methodologies are demonstrated. In Chapter 1, the first examples of inter-and intramolecular enantioselective conjugate alkenylations employing organostannanes are reported. A chiral, cationic Rh(I)-diene complex catalyzed the enantioselective conjugate addition of alkenylstannanes to benzylidene Meldrum’s acids in moderate enantiomeric ratios and yields. Notably, the cationic and anhydrous conditions required for the asymmetric alkenylation are complementary to existing protocols employing other alkenylmetals. In Chapter 2, a domino, one-pot formation of tetracyclic ketones from benzylidene Meldrum’s acids using Sc(OTf)3 via a [1,5]-hydride shift/cyclization/Friedel-Crafts acylation sequence is described. Respectable yields were obtained in accord with the ability to convert to the spiro-intermediate, and considering the formation of three new bonds: one C-H and two C-C bonds. An intriguing carbon-carbon bond cleavage was also serendipitously discovered as part of a competing reaction pathway. In Chapter 3, the pursuit of novel C-H bond transformations led to the development of non-carbonyl-stabilized rhodium carbenoid Csp3-H insertions. This methodology enabled the rapid synthesis of N-fused indolines and related complex heterocycles from N-aziridinylimines. By using a rhodium carboxamidate catalyst, competing processes were minimized and C-H insertions were found to proceed in moderate to high yields. Also disclosed is an expedient total synthesis of (±)-cryptaustoline, a dibenzopyrrocoline alkaloid, which highlights the methodology. In Chapter 4, the Lewis acid promoted substitution of Meldrum’s acid discovered during the course of the domino reaction was explored in detail. The protocol transforms unstrained quaternary and tertiary benzylic Csp3-Csp3 bonds into Csp3-X bonds (X = C, N, H) and has even shown to be advantageous with regards to synthetic utility over the use of alternative leaving groups for substitutions at quaternary benzylic centers. This reaction has a broad scope both in terms of suitable substrates and nucleophiles with good to excellent yields obtained (typically >90%).

Au cours de ce travail de nouvelles méthodes pour la formation de liaison C-N ont été développées. Dans la première partie de cette thèse une application de catalyse métal-ligand bifonctionnelle pour la réaction énantiosélective aza-Michael est démontrée. Dans la deuxième partie nous présentons le travail sur les cyclisations, en utilisant des alcaloïdes du quinquina facilement disponibles, comme catalyseurs des plus prometteurs, fournissant des β-amino-acides d’indoline avec jusqu'à 98% ee. Parmi eux, l’hydroquinidine ressort du lot comme étant le catalyseur donnant le meilleur excès énatiomérique. La troisième partie est liée à l'élaboration d'un nouveau processus intermoléculaires de diamination de styrènes, diènes et triènes, utilisant des bis-sulfonylimides comme source d'azote, en combinaison avec le diacétate de iodosobenzène, qui fournit une approche intéressante et efficace de diamines vicinales biologiquement et chimiquement important. La réaction peut être effectuée à température ambiante sans avoir besoin de protection par atmosphère inerte. / The concept of metal-ligand bifunctionality was successfully applied for an enantioselective aza-Michael reaction by employing well-defined ruthenium amido complexes. The catalyst was optimised and the corresponding chiral indoline β-amino acid derivatives were obtained with high enantioselectivities. Next, a straightforward enantioselective bifunctional organocatalytic approach was also developed. Employing hydroquinidine as catalyst the corresponding cyclic products were obtained in excellent enantioselectivities and quantitative yields. These compounds can be selectively deprotected and applied to peptide synthesis. Finally, we have developed unprecedented diamination reactions of styrenes, butadienes and hexatrienes employing easily accessible hypervalent iodine(III) reagents under robust reaction conditions. The first examples of the metal-free 1,2-diamination of butadienes were demonstrated and this oxidation methodology was further extended to the highly attractive 1,4 installation of two nitrogen atoms within a single step.