Rhodium-Promoted anti-Hydroboration of Terminal Alkynes via Combined Stoichiometric Reactions DOI

Laura A. de las Heras,

Miguel A. Esteruelas, Katarzyna Mituła

et al.

Organometallics, Journal Year: 2024, Volume and Issue: 44(1), P. 115 - 127

Published: Dec. 26, 2024

Reactions of RhH{κ3-P,O,P-[xant(PiPr2)2]} (xant(PiPr2)2 = 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) with 2 equiv tert-butylacetylene and phenylacetylene lead to the acetylide derivatives Rh(C≡CR){κ3-P,O,P-[xant(PiPr2)2]} (R tBu, Ph). The C–C triple bond these compounds undergoes B–H anti-addition pinacolborane (HBpin) produce Rh{(E)-C(Bpin)=CHR-Pro-Z}{κ3-P,O,P-[xant(PiPr2)2]} Ph), which regenerate in presence a new alkyne molecule, releasing respective (Z)-borylolefin. Complex Rh{(E)-C(Bpin)=CHPh-Pro-Z}{κ3-P,O,P-[xant(PiPr2)2]} is unstable toluene. Initially, double borylalkenyl ligand E Z isomerization Rh{(Z)-C(Bpin)═CHPh-Pro-E}{κ3-P,O,P-[xant(PiPr2)2]}, subsequently evolves aryl derivative Rh{C6H4-2-[E-CH═CH(Bpin)]}{κ3-P,O,P-[xant(PiPr2)2]}. latter reacts molecule Rh(C≡CPh){κ3-P,O,P-[xant(PiPr2)2]} (E)-borylolefin. According this reactivity, complex an effective catalyst precursor for hydroboration terminal alkynes mixtures (Z)- (E)-borylolefins. molar ratio between isomers depends on substituent alkyne; para-substituted substituents electron-withdrawing groups favor Z-borylolefin.

Language: Английский

Metal-catalyzed Markovnikov-type selective hydrofunctionalization of terminal alkynes DOI
Jieping Chen, Wen‐Ting Wei, Zhuocheng Li

et al.

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(14), P. 7566 - 7589

Published: Jan. 1, 2024

Metal-catalyzed highly Markovnikov-type selective hydrofunctionalization of terminal alkynes provides a straightforward and atom-economical route to access 1,1-disubstituted alkenes, which have wide range applications in organic synthesis. However, the transformations are challenging due electronic steric effects during addition process. With development metal-catalyzed synthesis, different metal catalysts been developed solve this challenge, especially for platinum group catalysts. In perspective, we review homogeneous according classified element types as well reaction mechanisms. Future avenues investigation also presented help expand exciting field.

Language: Английский

Citations

19

Regio‐ and Stereo‐Selective Isomerization of Borylated 1,3‐Dienes Enabled by Selective Energy Transfer Catalysis DOI Creative Commons

Byeongseok Kweon,

Lukas Blank,

Julia Soika

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(22)

Published: March 28, 2024

Abstract Configurationally‐defined dienes are pervasive across the bioactive natural product spectrum, where they typically manifest themselves as sorbic acid‐based fragments. These C 5 motifs reflect biosynthesis algorithms that facilitate their construction. To complement established biosynthetic paradigms, a chemical platform to construction of stereochemically defined, functionalizable by light‐enabled isomerization has been devised. Enabled selective energy transfer catalysis, variety substituted β‐boryl acid derivatives can be isomerized in regio‐ and stereo‐selective manner (up 97 : 3). Directionality is guided stabilizing n O →p B interaction product: this constitutes formal anti ‐hydroboration starting alkyne. This operationally simple reaction employs low catalyst loadings (1 mol %) complete 1 h. X‐ray analysis supports hypothesis leads chromophore bifurcation: provides structural foundation for transfer.

Language: Английский

Citations

7

trans-Ge/B 1,1-Hydroboration of Alkynylgermanes with 9-BBN DOI

Zi‐Long An,

Chao Chen, Alice Yu

et al.

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 23, 2025

A 1,1-hydroboration of alkynylgermanes with unique trans-Ge/B stereochemistry under transition-metal-free conditions is reported. Mechanistic studies suggest that a pathway involving α-boration followed by stepwise 1,2-Ge/H shift on the intermediate structurally lies between an alkyne-Ge+ π complex and typical vinyl cation. The resulting Ge/B bimetallic modules, along Ge*/Ge/B trimetallic variant, can be conveniently transformed into trisubstituted olefins through iterative divergent cross-coupling. This work demonstrates incorporating metalloids classical organic reactions may offer unconventional chemical selectivity efficient synthetic applications.

Language: Английский

Citations

1

Ligand-controlled regiodivergent Ni-catalyzed trans-hydroboration/carboboration of internal alkynes with B2pin2 DOI Creative Commons

Zunsheng Chen,

Biao Nie,

Xiaoning Li

et al.

Chemical Science, Journal Year: 2024, Volume and Issue: 15(6), P. 2236 - 2242

Published: Jan. 1, 2024

With the aid of directing group strategy, an approach for synthesis alkenyl and 1-naphthyl boronates with stereo- regioselectivity via ligand-controlled Ni-catalyzed trans -hydroboration/carboboration internal alkynes was developed.

Language: Английский

Citations

4

Visible-Light-Induced trans-Hydroboration of Diaryl Alkynes Utilizing Excited State of Borate Complexes DOI

Takahiro Komaki,

Yu Sato,

Masanobu Uchiyama

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: 26(11), P. 2180 - 2185

Published: March 11, 2024

We have developed visible-light-induced trans-hydroboration of diaryl alkynes via direct photoexcitation in-situ-generated diboron complexes, affording previously elusive (E)-1,2-diaryl-vinylboronates with high stereoselectivity. Experimental, spectroscopic, and theoretical mechanistic studies revealed that the triplet-state borate complex facilitates B–B bond cleavage desired C–B formation. This methodology does not require any catalyst is operationally simple. The highly borylated 1,2-diaryl alkenes [1-(2-borylphenyl)vinyl)boronates] are shown to be useful as building blocks.

Language: Английский

Citations

3

Theoretical Elucidation of Ru(II)-Catalyzed Gem-Hydrogenative Cycloisomerization and Sigmatropic Rearrangement of Propargyl Alcohol Derivatives DOI

Shuiqing Liu,

Baoping Ling, Siwei Bi

et al.

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 6, 2025

Gem-hydrogenative cycloisomerization and sigmatropic rearrangement reactions of propargyl alcohol derivatives with different Ru(II) catalysts afforded cyclopropanation, cyclopentenylation, cyclohexenylation, enol acetate, respectively. To understand the mechanism origin product selectivity, density functional theory calculations were performed. Calculated results reveal that electron-abundant neutral active catalyst [Cp*RuCl] facilitate formation a Cl- counterion-assisted π-back bonding between Ru σ* C-H, which decreases energy barrier agostic interaction determining cyclopropane product. Whereas, this enyne electron-deficient cationic [CpRu(MeCN)]+ is prone to cyclopentenylation through C-C bond 1,2-H shift, because beneficial for shift. With [CpRu(MeCN)]+, bearing methyl ether can facilely undergo ligand exchange afford ascribed strong Ru···O O (methyl ether). Conversely, bulky silyl unfavorable proceed cyclohexenylation due steric repulsion ether. The derivative attached nucleophilic substituent favorable experience [2,3]-sigmatropic rather than cycloisomerization, electrophilic ruthenium carbene.

Language: Английский

Citations

0

Expedient access to bora-butenolide bioisosteres by counteranion-mediated trans-hydroboration of alkynes DOI Creative Commons
Yu Liu, Yang Liu, Yuan F. Zheng

et al.

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: May 27, 2025

Abstract The hydroboration of alkynes is a textbook example syn -selective concerted addition reaction, while trans additions borane to remain be developed. We herein report transition metal-free anti -addition pinacolborane alkynes, facilitated by the counteranion effect. This work further develops Chan alkyne reduction utilizing instead aluminohydride reagents, enabling facile synthesis valuable five-membered boracycles that constitute isosteric alternatives bioactive butenolides and versatile platform for abundant downstream transformations. practical method distinguished excellent regioselectivity, broad substrate scope, high compatibility with variety functional groups. exploration patterns affords not only stereo-complementary approach traditional organic synthesis, but also mandates new perspective on noncanonical -hydroboration mechanism. A combination control experiments computational studies at DFT level theory reveal previously unrecognized role HMDS in stepwise intermolecular hydrogen transfer process.

Language: Английский

Citations

0

Regio‐ and Stereo‐Selective Isomerization of Borylated 1,3‐Dienes Enabled by Selective Energy Transfer Catalysis DOI Creative Commons

Byeongseok Kweon,

Lukas Blank,

Julia Soika

et al.

Angewandte Chemie, Journal Year: 2024, Volume and Issue: 136(22)

Published: March 28, 2024

Abstract Configurationally‐defined dienes are pervasive across the bioactive natural product spectrum, where they typically manifest themselves as sorbic acid‐based fragments. These C 5 motifs reflect biosynthesis algorithms that facilitate their construction. To complement established biosynthetic paradigms, a chemical platform to construction of stereochemically defined, functionalizable by light‐enabled isomerization has been devised. Enabled selective energy transfer catalysis, variety substituted β‐boryl acid derivatives can be isomerized in regio‐ and stereo‐selective manner (up 97 : 3). Directionality is guided stabilizing n O →p B interaction product: this constitutes formal anti ‐hydroboration starting alkyne. This operationally simple reaction employs low catalyst loadings (1 mol %) complete 1 h. X‐ray analysis supports hypothesis leads chromophore bifurcation: provides structural foundation for transfer.

Language: Английский

Citations

1

Development of organic photoreactions utilizing the characteristics of elements with low electronegativity DOI Creative Commons
Yuki Nagashima

Bulletin of the Chemical Society of Japan, Journal Year: 2024, Volume and Issue: 97(8)

Published: July 31, 2024

Abstract Organic photoreactions have received much attention as unique tools to access kinetically and/or thermodynamically prohibited products in the ground state. These been based mainly on using elements with high electronegativity such carbon (C), oxygen (O), nitrogen (N), halogens (F, Cl, Br, and I) well transition metals. On other hand, we interested characteristics of low electronegativity, boron (B), silicon (Si), tin (Sn), excited state, enabling highly reactive selective photoinduced borylations, silylations, stannylations. In this account, highlight our latest findings concerning diverse organic utilizing B, Si, Sn elements, which are challenging when conventional strategies.

Language: Английский

Citations

1

Selektive Kupplung von β‐(Borylvinyl)silanen durch eine Gold‐Katalysierte Hiyama‐Reaktion – ein Einfacher Weg zu Diaryl‐Substituierten Vinylboronaten DOI Creative Commons
Shan Zhang,

Jonas F. Wunsch,

Matthias Rudolph

et al.

Angewandte Chemie, Journal Year: 2024, Volume and Issue: 136(50)

Published: Aug. 15, 2024

Abstract Die Verwendung von diarylsubstituierten Vinylboronaten, einer Klasse chemischer Bausteine mit wohlbekanntem synthetischem Nutzen, ist hauptsächlich durch die Schwierigkeiten bei ihrer Herstellung begrenzt. Wir stellen hier eine bequeme synthetische Strategie vor, auf goldkatalysierten Hiyama‐Arylierung ( Z )‐β‐(Borylvinyl)silanen basiert, Hydroborierung Silylalkinen leicht zugänglich sind. Durch Ausnutzung der hoch elektronegativen Natur des Gold(III)‐Zwischenprodukts (das lichtunterstützte Oxidation Aryldiazoniumsalzen ist) wird selektive Aktivierung Silylgruppe in Gegenwart Boreinheit erreicht. Dies eröffnet einen Weg zur selektiven Synthese Diaryl‐substituierten Vinylboronaten. Reaktion weist breiten Substratbereich, ausgezeichnete Toleranz gegenüber funktionellen Gruppen und perfekte Chemoselektivität auf. experimentelle Studien Dichtefunktionaltheorie (DFT)‐Berechnungen konnten wir den Mechanismus aufklären. Das Potenzial wurde nachgeschaltete Transformationen demonstriert, einfachen zu bifunktionellen Phenanthrenen Triaryl‐substituierten Olefinen bieten.

Citations

0