Propargylic Dialkyl Effect for Cyclobutene Formation through Ir(III)-Catalyzed Cycloisomerization of 1,6-Enynes DOI

Xuanyu Zhu,

Yi Li,

Hongtao Luo

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: 26(4), P. 966 - 970

Published: Jan. 25, 2024

The propargylic dialkyl effect (PDAE) has a significant impact on the cyclization reaction of enynes, partly reflected in changing types products. Herein, we described influence Ir(III)-catalyzed cycloisomerization 1,6-enynes to provide strained cyclobutenes. A series substituted were proved be excellent substrate candidates presence [Cp*IrCl2]2 toluene. Mechanistic investigation, based deuterium labeling experiments and control experiments, indicated that might boost C(sp)-H activation by preventing coordination active iridium species C(sp)≡C(sp) bond enynes. This finding contributes fundamental understanding enyne reactions offers valuable insight into effect.

Language: Английский

Recent advances in the asymmetric catalytic synthesis of chiral 3-hydroxy and 3-aminooxindoles and derivatives: Medicinally relevant compounds DOI
Pedro Brandão, Anthony J. Burke

Tetrahedron, Journal Year: 2018, Volume and Issue: 74(38), P. 4927 - 4957

Published: June 11, 2018

Language: Английский

Citations

44
Electrooxidative iridium-catalyzed sp2 C−H activation-annulation leading to cationic π-extended heteroaromatics DOI
Qi‐Liang Yang, Nana Guo,

Shu-Xian Liu

et al.

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(17), P. 4849 - 4856

Published: Jan. 1, 2024

An electrochemically driven, Cp*Ir( iii )-catalyzed method for alkenyl and aromatic C(sp 2 )–H activation coupling with alkynes the synthesis of biologically useful quaternary ammonium salts under mild conditions is demonstrated.

Language: Английский

Citations

3
Total Synthesis of Tambromycin Enabled by Indole C–H Functionalization DOI
Galen P. Miley,

Jennifer C. Rote,

Richard B. Silverman

et al.

Organic Letters, Journal Year: 2018, Volume and Issue: 20(8), P. 2369 - 2373

Published: March 27, 2018

The total synthesis of tambromycin (1), a recently isolated tetrapeptide, is reported. This unusual natural product possesses highly modified tryptophan-derived indole fragment fused to an α-methylserine-derived oxazoline ring, and unique noncanonical amino acid residue named tambroline (11). A convergent was achieved by 13-step route that leveraged recent developments in the field C–H functionalization prepare complex fragment, as well efficient featured diastereoselective amination homoproline.

Language: Английский

Citations

27
Transition-Metal-Catalyzed Transformations for the Synthesis of Marine Drugs DOI Creative Commons

Lucía G. Parte,

Sergio Fernández,

Eva Sandonís

et al.

Marine Drugs, Journal Year: 2024, Volume and Issue: 22(6), P. 253 - 253

Published: May 29, 2024

Transition metal catalysis has contributed to the discovery of novel methodologies and preparation natural products, as well new chances increase chemical space in drug programs. In case marine drugs, this strategy been used achieve selective, sustainable efficient transformations, which cannot be obtained otherwise. perspective, we aim showcase how a variety transition metals have provided fruitful couplings wide drug-like scaffolds over past few years, by accelerating production these valuable molecules.

Language: Английский

Citations

2
Identification, semisynthesis, and anti-inflammatory evaluation of 2,3-seco-clavine-type ergot alkaloids from human intestinal fungus Aspergillus fumigatus CY018 DOI
Juan Zhang, Wen‐Yu Zhao, Chao Wang

et al.

European Journal of Medicinal Chemistry, Journal Year: 2021, Volume and Issue: 224, P. 113731 - 113731

Published: July 29, 2021

Language: Английский

Citations

16
Understanding the Activation of Air-Stable Ir(COD)(Phen)Cl Precatalyst for C–H Borylation of Aromatics and Heteroaromatics DOI

Eric D. Slack,

Thomas J. Colacot

Organic Letters, Journal Year: 2021, Volume and Issue: 23(5), P. 1561 - 1565

Published: Feb. 5, 2021

A newly developed robust catalyst [Ir(COD)(Phen)Cl] (A) was used for the C–H borylation of three dozen aromatics and heteroaromatics with excellent yield selectivity. Activation identified by use catalytic amounts water, alcohols, etc., when B2pin2 in noncoordinating solvents, while THF HBpin required. The results were on par situ based expensive system [Ir(OMe)(COD)]2/dtbbpy or Me4Phen.

Language: Английский

Citations

15
Ruthenium Catalyzed Intramolecular C−X (X=C, N, O, S) Bond Formation via C−H Functionalization: An Overview DOI

Pallavi Singh,

Kishor Kumar Chouhan,

Arup Mukherjee

et al.

Chemistry - An Asian Journal, Journal Year: 2021, Volume and Issue: 16(17), P. 2392 - 2412

Published: July 12, 2021

Abstract Ruthenium catalyzed C−H activation is well known for its high tolerance towards the functional group and broad applicability in organic synthesis molecular sciences, with significant applications pharmaceutical industries, material polymer industry. In last few decades, enormous progress has been observed ruthenium‐catalyzed chemistry. Notably, vast majority of functionalization literature are intermolecular, although intramolecular variant provides fascinating new structural facet starting from simple scaffolds. Intramolecular atom economical step efficient, results less formation undesired products which easy to purify. This created a lot interest chemistry developing synthetic strategies such functionalization. The focus this review present relatively unexplored bonds into C−X (X=C, N, O, S) utilizing versatile ruthenium catalysts, their scope, brief mechanistic discussion.

Language: Английский

Citations

15
Synthesis of Four Illudalane Sesquiterpenes Utilizing a One-Pot Diels–Alder/Oxidative Aromatization Sequence DOI
Miao‐Miao Xun,

Yunli Bai,

Yanhong Wang

et al.

Organic Letters, Journal Year: 2019, Volume and Issue: 21(17), P. 6879 - 6883

Published: Aug. 23, 2019

The concise, divergent total syntheses of four illudalane sesquiterpenes using an indanone as the key intermediate are reported. elements in these syntheses, which involve only to six operational steps, consist a Suzuki cross-coupling and one-pot Diels–Alder/oxidative aromatization reaction.

Language: Английский

Citations

17
Total Synthesis of α‐Tocopherol through Enantioselective Iridium‐Catalyzed Fragmentation of a Spiro‐Cyclobutanol Intermediate DOI

Friederike Ratsch,

Waldemar Schlundt,

Dominik Albat

et al.

Chemistry - A European Journal, Journal Year: 2019, Volume and Issue: 25(19), P. 4941 - 4945

Published: Feb. 11, 2019

Abstract A conceptionally new strategy for the asymmetric (2 R ‐selective) synthesis of α‐tocopherol (vitamin E) was developed. In stereocontrolled key step, a prochiral spiro[chromane‐2,3′‐cyclobutanol] unit is effectively desymmetrized under C−C bond activation in an unprecedented iridium‐catalyzed transformation using ( S )‐DTBM‐SegPhos as chiral ligand (e.r. 97:3). To complete synthesis, side chain attached through Ru‐catalyzed cross‐metathesis employing alkene derived from , )‐hexahydrofarnesol. suppress epimerization during final hydrogenation, PtO 2 had to be used catalyst instead Pd/C. alternative approach (employing propargyl‐substituted spiro‐cyclobutanol), constructed prior Ir‐catalyzed ring fragmentation (>99:1 d.r.) enyne (using )‐dihydrocitronellal) followed by Cr‐catalyzed 1,4‐hydrogenation and (diastereoselective) Pfaltz hydrogenation resulting triple‐substituted olefin. The work demonstrates potential iridium catalysis enantioselective activation.

Language: Английский

Citations

16
Samarium(III) Triflate in Organic Synthesis: a Mild and Efficient Catalyst DOI

Asish Kumar Dey,

Sasadhar Majhi

ChemistrySelect, Journal Year: 2023, Volume and Issue: 8(18)

Published: May 9, 2023

Abstract Lanthanides have shown great potential in the field of magnetic materials, telecommunications, hard‐disk drives, catalysis, medicine, agriculture, and more. Recently, lanthanide complexes gained significant attention cancer diagnosis therapy because multifunctional chemical activities lanthanide‐ion 4 f electronic configuration. Among lanthanides, samarium metal its derivatives been subject many applications organic transformations. Various triflates such as Bi(OTf) 3 , Yb(OTf) In(OTf) Sc(OTf) Er(OTf) Ce(OTf) Sm(OTf) others play a profound role developing novel eco‐friendly protocols synthesis with excellent efficiency selectivity. triflate, samarium(III) triflate has remarkable contribution synthesizing promising molecules it to be moisture tolerant reusable Lewis catalyst under mild conditions. The present review aims focus on different useful using an efficient for first time elegantly.

Language: Английский

Citations

5