Showing papers by "Fumitoshi Kakiuchi published in 2021"
TL;DR: In this paper, a C-H homoallylation reaction of aromatic ketones with methylenecyclopropanes (MCPs) using a catalytic amount of Fe(PMe3)4 was reported.
Abstract: We report here a C–H homoallylation reaction of aromatic ketones with methylenecyclopropanes (MCPs) only using a catalytic amount of Fe(PMe3)4. A variety of aromatic ketones and MCPs are applicable...
22 citations
TL;DR: In this article, a novel method for catalytic remote bismetalation of alkene substrates by the addition of dimetal reagents is accomplished by using chain walking.
Abstract: A novel method for catalytic remote bismetalation of alkene substrates by the addition of dimetal reagents is accomplished by using chain walking. In the presence of a palladium catalyst, the reaction of various 1,n-dienes and diborons were converted into cyclopentane derivatives with two boryl groups at remote positions via facile regioselective transformation of an unactivated sp3 C-H bond to a C-B bond. Sequential construction of three distant bonds, which is difficult to achieve by any method, was accomplished for the reactions of 1,n-dienes (n ≥ 7).
17 citations
TL;DR: In this article, a transition-metal-catalyzed electrochemical C-H functionalization of arylpyridines and benzamide derivatives using HCl/HBr and I2 as a halogen source is described.
Abstract: Transition-metal-catalyzed electrochemical C-H functionalizations have been extensively studied as atom- and step-economical clean methods in organic synthesis. In this account, we described our efforts on the palladium-catalyzed electrochemical C-H functionalizations, including C-H halogenations of arylpyridines and benzamide derivatives using HCl/HBr and I2 as a halogen source, a one-pot process giving teraryls via the palladium-catalyzed electrochemical C-H iodination and subsequent Suzuki-Miyaura coupling, and an iodine-mediated oxidative homo-coupling reaction of arylpyridines.
8 citations
TL;DR: Palladium-catalyzed remote arylative substitution was achieved for the reaction of aryboronic acids with alkenes possessing a distant acetoxy group to provide arylation products having an alkene moiety at the remote position as discussed by the authors.
Abstract: Palladium-catalyzed remote arylative substitution was achieved for the reaction of arylboronic acids with alkenes possessing a distant acetoxy group to provide arylation products having an alkene moiety at the remote position. The use of β-acetoxy elimination as a key step in the catalytic cycle allowed for regioselective formation of unstabilized alkenes after chain walking. This reaction was applicable to various arylboronic acids as well as alkene substrates.
7 citations
TL;DR: In this article, an 8-quinolinolato rhodium catalyst was used to form aldimines and enamines in high yields with high functional group tolerance including hydroxy, bromo, cyano, and thioester groups.
Abstract: Anti-Markovnikov hydroamination of both aliphatic and aromatic terminal alkynes with primary amines was achieved using an 8-quinolinolato rhodium catalyst to form aldimines and enamines in high yields. This catalytic system realized high functional group tolerance including hydroxy, bromo, cyano, and thioester groups.
3 citations
TL;DR: In this paper, 2:1 and 1:1 couplings of alkylacetylenes with secondary amines were achieved using 8-quinolinolato rhodium catalysts and CsF.
3 citations
TL;DR: Deuterium-labeling experiments were performed for the Fe(PMe3)4-catalyzed C-H/olefin coupling using a deuteriumlabeled aromatic ketone with various alkenes as mentioned in this paper.
Abstract: Deuterium-labeling experiments were performed for the Fe(PMe3)4-catalyzed C–H/olefin coupling using a deuterium-labeled aromatic ketone with various alkenes. While the reactions with a variety of alkenes provided the linear alkylation products formed via 1,2-insertion of alkene into an Fe–H bond, the reversible 2,1-insertion proceeded during the reaction highly depends on the choice of the alkene. No H/D scrambling resulting from 2,1-insertion/β-elimination was detected for the reactions with a vinylsilane and N-vinylcarbazole, but the reactions with styrenes are considered to involve rapid 2,1-insertion/ β-elimination processes to cause significant levels of H/D scrambling.
2 citations
1 citations
01 Jan 2021
TL;DR: In this article, the ruthenium-catalyzed arylation reactions of C-H and C-O bonds in aromatic ketones with (hetero)arylboronates were described.
Abstract: The efficient, short-step synthesis of substituted polycyclic aromatic hydrocarbons (PAHs) via the ruthenium-catalyzed arylation reactions of C–H and C–O bonds in aromatic ketones with (hetero)arylboronates were described in this chapter. The C–H arylation of anthraquinone with arylboronates using RuH2(CO)(PPh3)3 as a catalyst gave 1,4,5,8-tetraarylanthraquinones, and then, it was converted to multiarylanthracenes by transformations of the carbonyl groups. Dibenzo[a,h]anthracenes and picenes were synthesized by utilizing the coupling reaction of acetophenones with (hetero)aryldiboronates and transformations of the acetyl groups. Sequential functionalization of the carbonyl group, that is, methylenation and dehydrogenative cyclization, in tetraarylanthraquinones gave 3,6,14,16-tetrasubstituted-tetrabenzo[a,d,j,m]coronenes. The stepwise ruthenium-catalyzed C–O and C–H arylation reactions of 1,4-dimethoxyanthraquinone gave tetraarylanthraquinones possessing two different aryl groups. These anthraquinones were converted to the 3,6,13,16-tetrasubstituted-tetrabenzo[a,d,j,m]coronenes having different substituents by the same carbonyl group transformations. Dibenzo[h,rst]pentaphenes and dibenzo[fg,qr]pentacenes were synthesized by combining the ruthenium-catalyzed chemoselective C–O arylation of 1,4- and 1,5-dimethoxyanthraquinones, Corey-Chaykofsky reaction, and Lewis acid-catalyzed dehydrative aromatization.