Atroposelective Ir-Catalyzed C–H Borylation of Phthalazine Heterobiaryls DOI Creative Commons

Paul Stehrer,

Anke Spannenberg,

Marko Hapke

et al.

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(19), P. 14222 - 14226

Published: Sept. 26, 2023

The atroposelective iridium-catalyzed borylation of menthyloxy-substituted phthalazine heterobiaryls with diborons is reported. Utilizing [Ir(OMe)(COD)]2/2-aminopyridine as a rarely used efficient catalyst system, the were selectively borylated in 2-position carbocycle, exclusively yielding only one atropisomers, depending on substitution (+)-menthyl or (-)-menthyl moieties. Exemplary further functionalization atropisomer demonstrated that nickel-catalyzed Suzuki-Miyaura cross-coupling an aryl halide was able to provide stereoretention certain degree (up 75% de).

Language: Английский

Kinetic and thermodynamic control of C(sp 2 )–H activation enables site-selective borylation DOI
Jose B. Roque, Alex M. Shimozono, Tyler P. Pabst

et al.

Science, Journal Year: 2023, Volume and Issue: 382(6675), P. 1165 - 1170

Published: Dec. 7, 2023

Catalysts that distinguish between electronically distinct carbon-hydrogen (C–H) bonds without relying on steric effects or directing groups are challenging to design. In this work, cobalt precatalysts supported by N -alkyl-imidazole–substituted pyridine dicarbene (ACNC) pincer ligands described enable undirected, remote borylation of fluoroaromatics and expansion scope include electron-rich arenes, pyridines, tri- difluoromethoxylated thereby addressing one the major limitations first-row transition metal C–H functionalization catalysts. Mechanistic studies established a kinetic preference for bond activation at meta -position despite cobalt-aryl complexes resulting from ortho being thermodynamically preferred. Switchable site selectivity in as function boron reagent was preliminarily demonstrated using single precatalyst.

Language: Английский

Citations

23
Catalyst Design for Rh-Catalyzed Arene and Alkane C–H Borylation: The NHC Affects the Induction Period, and Indenyl is Superior to Cp DOI Creative Commons
Paul A. Morton,

Abigayle L. Boyce,

Anamarija Pišpek

et al.

Organometallics, Journal Year: 2024, Volume and Issue: 43(9), P. 974 - 986

Published: March 28, 2024

In order to establish design criteria for Rh C–H borylation catalysts, analogues of the successful catalyst [Rh(Ind)(SIDipp)(COE)] (Ind = η5-indenyl, SIDipp 1,3-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene, and COE cis-cyclooctene) were synthesized by changing indenyl carbene ligands. [RhCp(SIDipp)(COE)] (1) formed alongside C–C activated, cyclometalated byproduct [RhCp(κ2CAr,Ccarbene-SIDipp′)(iPr)] (rac-2; SIDipp′ 1-(6-isopropylphenyl)-3-(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene). Computational modeling dissociation showed that both activation aryl group is thermally attainable reversible under experimental conditions, with products being more thermodynamically stable species. Oxidative addition 1 SiH(OEt)3 gave silyl hydride [RhCp(H){Si(OEt)3}(SIDipp)] (rac-3). [Rh(Ind)(IDipp)(COE)] (4; IDipp 1,3-bis(2,6-diisopropylphenyl)-imidazole-2-ylidene), carbonyl analogue [Rh(Ind)(IDipp)(CO)] (5; νCO 1940 cm–1, cf. 1944 cm–1 [Rh(Ind)(SIDipp)(COE)]), [Rh(Ind)(IMe4)(COE)] (6; IMe4 1,3,4,5-tetramethylimidazol-2-ylidene) also characterized, but attempts synthesize complexes fluorenyl or 1,2,3,4-tetrahydrofluorenyl ligands not successful. For catalytic benzene using B2pin2, was inactive at 80 °C, superior all other tested due shortest induction period. However, HBpin precatalyst 4 eliminated Catalytic n-alkane [Rh(Ind)(NHC)(COE)] yields up 21% alkylBpin, [RhCp*(C2H4)2] better catalyst.

Language: Английский

Citations

2
Transfer C–H borylation of alkenes under Rh(I) catalysis: Insight into the synthetic capacity, mechanism, and selectivity control DOI Creative Commons
Lukas Veth,

Hanusch A. Grab,

Sebastián Martínez

et al.

Chem Catalysis, Journal Year: 2022, Volume and Issue: 2(4), P. 762 - 778

Published: March 11, 2022

Language: Английский

Citations

8
Metal-free C–H Borylation and Hydroboration of Indoles DOI Creative Commons
Pinaki Nad, Arup Mukherjee

ACS Omega, Journal Year: 2023, Volume and Issue: 8(41), P. 37623 - 37640

Published: Oct. 2, 2023

The C–H borylation and hydroboration reactions have emerged as promising synthetic tools to construct organoboron compounds. Organoboron compounds of N-heterocycles, particularly indole derivatives, found widespread application in a variety fields. As result, considerable advancement the area indoles was observed last few decades. Among various methods applied, metal-free approach has received special attention. This mini-review discusses recent progress under conditions, their scope, brief mechanistic studies.

Language: Английский

Citations

4
Borylative Difunctionalization of Unsaturated Hydrocarbons Using Borylcopper Species DOI
Tetsuaki Fujihara

Synlett, Journal Year: 2023, Volume and Issue: 35(02), P. 196 - 204

Published: April 26, 2023

Abstract This account summarizes the Cu-catalyzed borylative functionalizations of unsaturated hydrocarbons that we have developed over past decade. First, focus on regioselective hydroboration unsymmetrical internal alkynes and 1,2-dienes. Secondly, a allyl–allyl coupling using 1,2-dienes, B2pin2, an allyl phosphate is presented. Thirdly, introduce boroacylation boroformylation 1,2-dienes by acid anhydride or formate, respectively, as electrophile. Lastly, describe synthesis 2-boryl-1,3-butadienes cyclic allylborates. These reactions offer versatile method for synthesizing broad range useful compounds also provide detailed understanding reaction mechanism, which could lead to development catalysts are both more efficient selective. 1 Introduction 2 Hydroboration Alkynes 3 1,2-Dienes 1,3-Dienes 4 Synthesis 2-Boryl-1,3-butadienes 5 Boroallylation 6 Boroacylation 7 Boroformylation 8 Cyclic Allylborates 9 Conclusion Outlook

Language: Английский

Citations

3
Examining the Scope of Deriving β-Aryl Enones from Enol Silanes as Ketone Equivalents via Pd(II)-Mediated Sequential Dehydrosilylation and Arylation DOI

Subba Rao Polimera,

Andivelu Ilangovan, Murugaiah A. M. Subbaiah

et al.

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(11), P. 7256 - 7271

Published: May 16, 2023

Silyl enol ethers were examined as a masked source of saturated ketones to derive β-aryl enones and their derivatives by dehydrosilylation generate in situ subsequent oxidative arylation with arylboronic acids transmetallation coupling partners using relayed Pd(II) catalysis one pot under base-free conditions. Oxygen was found be an efficient green oxidant enable both silanes arylation. Additionally, conditions can custom-designed take advantage aryl halides alternative arylating agents. The preparative scope investigated 35 examples (up 95% yield), mechanistic studies implied cationic Pd(II)-based catalytic system.

Language: Английский

Citations

1
π–π stacking assisted regioselectivity regulation in palladium-catalyzed cyclization reactions: a theoretical study DOI Creative Commons
Song Liu,

Dianmin Zhang,

Yue Gong

et al.

RSC Advances, Journal Year: 2024, Volume and Issue: 14(51), P. 38285 - 38292

Published: Jan. 1, 2024

Manipulating the structural differences in reaction substrates leads to formation of distinct products. Computational evidence that supported a π–π stacking assisted regioselectivity regulatory mechanism was presented.

Language: Английский

Citations

0
Copper‐Catalyzed Simultaneous Installation of Boryl and Carbonyl Functionalities to Unsaturated Hydrocarbons DOI
Tetsuaki Fujihara

Asian Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 11(12)

Published: Oct. 22, 2022

Abstract Cu‐catalyzed borylative functionalization of unsaturated hydrocarbons is an effective method for synthesizing various organoboron compounds under mild reaction conditions. In particular, installing carbonyl functionalities such as acyl, formyl, and carboxy groups interesting because the essential role these in organic synthesis. This review focuses on installation boryl using Cu catalysts. First, formylation acylation reactions formate esters, acyl halides, or acid anhydrides are addressed. Second, simultaneous incorporation a group carbon dioxide electrophile summarized. Third, borocyanation electrophilic cyanation reagents described.

Language: Английский

Citations

2
Density Functional Theory Studies of the Catalyst Structure–Activity and Selectivity Relationships in Rh(I)-Catalyzed Transfer C–H Borylation of Alkenes DOI
Sebastián Martínez, Paweł Dydio

Organometallics, Journal Year: 2022, Volume and Issue: 41(13), P. 1649 - 1658

Published: June 23, 2022

We report the results of a computational investigation that shed light on catalyst structure–activity and selectivity relationships for our recently developed Rh(I)-xantphos-catalyzed transfer C–H borylation alkenes. Our study uncovered influence ligand properties have free energy surfaces reactions catalyzed by series Rh catalysts bearing derivatives xantphos with varied electronic features steric demands. present full reaction profiles provide closer look how different modifications to structure each step catalytic reaction. observed increased effects large effect surfaces, increasing barriers, thereby decreasing rates In turn, can stabilize key transition states destabilize crucial intermediates, such as resting catalyst, thus accelerating overall process. Additionally, modify relative alternative pathways therefore affect preferences. general, provides guidelines rational development new further enhance performance system address remaining challenges.

Language: Английский

Citations

1
Mechanism determination on [LCu-Fp] heterobimetallic-catalyzed C-H borylation of benzene and regioselectivity regulation: A DFT investigation DOI
Yuanyuan Sun, Yanli Zeng, Lingpeng Meng

et al.

Molecular Catalysis, Journal Year: 2023, Volume and Issue: 547, P. 113304 - 113304

Published: June 12, 2023

Language: Английский

Citations

0