The Stille reaction has established itself as one of the two most general and most selective palladium-catalyzed cross-coupling reactions, along with the Suzuki cross-coupling of organoboron compounds. The Stille coupling of α-alkoxystannanes is a relatively unexplored area. A previous study showed that an α-alkoxyalkylstannane could be coupled with benzoyl chloride with retention of configuration. However, our group has recently shown that Stille couplings of sulfonamidobenzylstannanes proceeds with inversion of configuration. In order to determine whether the Stille coupling reaction of α-alkoxybenzylstannanes proceeds with inversion or retention, the stereochemistry in the Stille reaction of α-alkoxybenzylstannanes was studied. Optimized conditions for Stille coupling of α-alkoxybenzyl-tributylstannanes with benzoyl chloride were developed: highest yields were observed using Pd2dba3 and PPh3 in toluene. Enantiomerically enriched α-hydroxystannanes were obtained via chromatographic resolution of diastereomeric carbamate derivatives. An X-ray crystal structure was obtained for the 3,5-dinitrobenzoate derivative of (S)-1-hydroxyphenylmethyl-trimethylstannane. Stille coupling (cat. Pd2dba3, PPh3, toluene) of the corresponding acetate with benzoyl chloride provided the acetate of (R)-benzoin thus establishing retention of configuration under these reaction conditions.

The Stille reaction has established itself as one of the two most general and most selective palladium-catalyzed cross-coupling reactions, along with the Suzuki cross-coupling of organoboron compounds. The Stille coupling of α-alkoxystannanes is a relatively unexplored area. A previous study showed that an α-alkoxyalkylstannane could be coupled with benzoyl chloride with retention of configuration. However, our group has recently shown that Stille couplings of sulfonamidobenzylstannanes proceeds with inversion of configuration. In order to determine whether the Stille coupling reaction of α-alkoxybenzylstannanes proceeds with inversion or retention, the stereochemistry in the Stille reaction of α-alkoxybenzylstannanes was studied. Optimized conditions for Stille coupling of α-alkoxybenzyl-tributylstannanes with benzoyl chloride were developed: highest yields were observed using Pd2dba3 and PPh3 in toluene. Enantiomerically enriched α-hydroxystannanes were obtained via chromatographic resolution of diastereomeric carbamate derivatives. An X-ray crystal structure was obtained for the 3,5-dinitrobenzoate derivative of (S)-1-hydroxyphenylmethyl-trimethylstannane. Stille coupling (cat. Pd2dba3, PPh3, toluene) of the corresponding acetate with benzoyl chloride provided the acetate of (R)-benzoin thus establishing retention of configuration under these reaction conditions.

No / A new method for the synthesis of meso-substituted porphyrins is described: reaction of 5,10,15,20-tetrabromoporphine magnesium complex with aryl or heteroaryl boronic acids in the presence of Pd(PPh3)4 gave meso-substituted porphyrins in yields up to 70%.

<i>N</i>-heterocyclic carbenes (NHC) have widely been used as spectator ligands in organometallic chemistry. Chelating bidentate di-<i>N-</i>heterocyclic carbenes (diNHC) provide additional entropic stability to their complexes relative to monodentate analogues. The steric and electronic environment around the metal centre can be fine-tuned by varying the substituents on the nitrogen atoms of the diNHC ligand. Synthesis and characterization of air and moisture stable bis(diimidazolylidene)nickel(II) complexes, [(diNHC)2Ni]2+, and their corresponding silver(I) and palladium(II) analogues are described.<p> Investigations into the catalytic potential of diNHC complexes of nickel as an alternative to palladium systems in carbon-carbon coupling reactions are discussed. In the Suzuki-Miyaura coupling reaction, the [(diNHC)2Ni]2+ complex was active for the coupling of aryl chlorides as well as aryl fluorides. The analogously synthesized Pd(II) complexes resulted in formation of (diNHC)PdCl2 species which were not active for the coupling of aryl fluorides. Transition-metal free coupling reactions were investigated and the results indicated that in the Mizoroki-Heck reaction, aryl iodides could be activated in the absence of nickel or palladium precatalysts when using Na2CO3 or NEt3 as base, while in the Suzuki-Miyaura reaction, aryl iodides and aryl bromides could be activated without any precatalyst when K3PO4 was used as base.<p> A general route into the synthesis of non-symmetrically substituted ligand precursors has been developed. Synthesis and characterization of non-symmetrically substituted ligand precursors, and their corresponding silver(I), palladium(II) and nickel(II) complexes are described. The activity of one of the non-symmetrically substituted (diNHC)Pd(II) complexes in the Suzuki-Miyaura coupling reaction of bulky substrates has been investigated. Non-symmetrically substituted diNHC ligand precursors with a hemi-labile pyridine arm have been synthesized and their corresponding Ni(II) and Pd(II) complexes are described.<p> Attempts to synthesize three-coordinate Pd(II) complexes using bulky â-diketiminato ligands are also discussed.

<i>N</i>-heterocyclic carbenes (NHC) have widely been used as spectator ligands in organometallic chemistry. Chelating bidentate di-<i>N-</i>heterocyclic carbenes (diNHC) provide additional entropic stability to their complexes relative to monodentate analogues. The steric and electronic environment around the metal centre can be fine-tuned by varying the substituents on the nitrogen atoms of the diNHC ligand. Synthesis and characterization of air and moisture stable bis(diimidazolylidene)nickel(II) complexes, [(diNHC)2Ni]2+, and their corresponding silver(I) and palladium(II) analogues are described.<p> Investigations into the catalytic potential of diNHC complexes of nickel as an alternative to palladium systems in carbon-carbon coupling reactions are discussed. In the Suzuki-Miyaura coupling reaction, the [(diNHC)2Ni]2+ complex was active for the coupling of aryl chlorides as well as aryl fluorides. The analogously synthesized Pd(II) complexes resulted in formation of (diNHC)PdCl2 species which were not active for the coupling of aryl fluorides. Transition-metal free coupling reactions were investigated and the results indicated that in the Mizoroki-Heck reaction, aryl iodides could be activated in the absence of nickel or palladium precatalysts when using Na2CO3 or NEt3 as base, while in the Suzuki-Miyaura reaction, aryl iodides and aryl bromides could be activated without any precatalyst when K3PO4 was used as base.<p> A general route into the synthesis of non-symmetrically substituted ligand precursors has been developed. Synthesis and characterization of non-symmetrically substituted ligand precursors, and their corresponding silver(I), palladium(II) and nickel(II) complexes are described. The activity of one of the non-symmetrically substituted (diNHC)Pd(II) complexes in the Suzuki-Miyaura coupling reaction of bulky substrates has been investigated. Non-symmetrically substituted diNHC ligand precursors with a hemi-labile pyridine arm have been synthesized and their corresponding Ni(II) and Pd(II) complexes are described.<p> Attempts to synthesize three-coordinate Pd(II) complexes using bulky â-diketiminato ligands are also discussed.

No description available.

Dimethoxynaphthalene (donor) and quinone (acceptor) have been chosen as a suitable redox pair and are bonded to either permethylated silane chains or corresponding permethylated alkyl chains to form Acceptor-(Bridge)-Donor molecules. The idea that the s-delocalization phenomenon of silane chains may greatly facilitate ET reactions will be tested. The starting material for the donor precursor, 4-(1,4-dimethoxynaphthyl)bromocyclohexane, was 1,4-naphthoquinone. After methylation and bromination, the Grignard reagent of the resulting bromide was reacted with cyclohexanedione, mono ethylene ketal. The resulting alcohol was changed to the donor precursor through the following functional group transformation steps: dehydration, hydrogenation, deketalization and bromination. 1,4-Dibenzyloxybromobenzene, the precursor for the acceptor, was synthesized from 1,4-hydroquinone through bromination and benzylation. The connection of the two precursors and either permethylated silane chains or permethylated alkyl chains will give the final target molecules for ET research. Progress on this is included.

Thesis advisor: James P. Morken / This thesis will describe the development of two transition metal catalyzed syntheses of organoboronic compounds. The first section describes relevant concepts and precedents for the conjunctive coupling reaction. In the second section of this thesis, nickel catalyzed conjunctive coupling reaction of carboxylic acid derivatives with 9-BBN derived ate complexes will be discussed, where beta-trialkylboryl ketones are obtained as the product. In the third section, the development of alkyl group migration in nickel-catalyzed conjunctive coupling with C(sp3) electrophiles will be discussed. Enantioenriched secondary boronic esters can be prepared from this reaction, and two alkaloid syntheses are disclosed as the application of the method. / Thesis (MS) — Boston College, 2020. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19516号 / 理博第4176号 / 新制||理||1600(附属図書館) / 32552 / 京都大学大学院理学研究科化学専攻 / (主査)教授 大須賀 篤弘, 教授 丸岡 啓二, 教授 依光 英樹 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20205号 / 理博第4290号 / 新制||理||1616(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 依光 英樹, 教授 大須賀 篤弘, 教授 丸岡 啓二 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM