Bidentate Directing Groups: An Efficient Tool in C–H Bond Functionalization Chemistry for the Expedient Construction of C–C Bonds

Chemical Reviews, Journal Year: 2020, Volume and Issue: 120(3), P. 1788 - 1887

Published: Jan. 6, 2020

During the past decades, synthetic organic chemistry discovered that directing group assisted C–H activation is a key tool for expedient and siteselective construction of C–C bonds. Among various strategies, bidentate groups are now recognized as one most efficient devices selective functionalization certain positions due to fact its metal center permits fine, tunable, reversible coordination. The family permit types assistance be achieved, such N,N-dentate, N,O-dentate, N,S-dentate auxiliaries, which categorized based on coordination site. In this review, we broadly discuss bond reactions formation bonds with aid groups.

Language: Английский

---

Rhodium‐Catalyzed C(sp²)‐ or C(sp³)−H Bond Functionalization Assisted by Removable Directing Groups

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 58(25), P. 8304 - 8329

Published: Oct. 12, 2018

Abstract In recent years, transition‐metal‐catalyzed C−H activation has become a key strategy in the field of organic synthesis. Rhodium complexes are widely used as catalysts variety functionalization reactions because their high reactivity and selectivity. The availability number rhodium various oxidation states enables diverse reaction patterns to be obtained. Regioselectivity, an important issue chemistry, can accomplished by using directing group assist reaction. However, obtain target functionalized compounds, it is also necessary use that easily removed. A wide range directed catalyzed have been reported date. this Review, we discuss Rh‐catalyzed aided removable such phenol, amine, aldehyde, ketones, ester, acid, sulfonic N‐heteroaromatic derivatives.

Language: Английский

---

The Comparison between Single Atom Catalysis and Surface Organometallic Catalysis

Chemical Reviews, Journal Year: 2019, Volume and Issue: 120(2), P. 734 - 813

Published: Oct. 15, 2019

Single atom catalysis (SAC) is a recent discipline of heterogeneous for which single on surface able to carry out various catalytic reactions. A kind revolution in by metals it was assumed that specific sites or defects nanoparticle were necessary activate substrates In another extreme the spectrum, organometallic chemistry (SOMC), and, extension, (SOMCat), have demonstrated atoms surface, but this time with ligands, could lead more predictive approach catalysis. The character SOMCat just result intuitive mechanisms derived from elementary steps molecular chemistry. This review article will compare aspects and considering several reactions, some exist both fields, whereas others might see mutual overlap future. After definition domains, detailed methods, mostly modeling spectroscopy, be followed analysis reactions: hydrogenation, dehydrogenation, hydrogenolysis, oxidative alkane cycloalkane metathesis, methane activation, metathetic oxidation, CO2 activation cyclic carbonates, imine selective reduction (SCR) prospective resulting present knowledge showing emergence new between two areas.

Language: Английский

---

Cp*Co(III)/MPAA-Catalyzed Enantioselective Amidation of Ferrocenes Directed by Thioamides under Mild Conditions

Organic Letters, Journal Year: 2019, Volume and Issue: 21(6), P. 1895 - 1899

Published: March 6, 2019

Cp*Cobalt(III)-catalyzed enantioselective C-H amidation of ferrocenes using monoprotected amino acids (MPAAs) as chiral ligands was developed. The reaction performed under mild conditions in high yields (up to 97%) with moderate enantioselectivity 77.5:22.5 er), providing a promising strategy create planar chirality via base-metal-catalyzed activation.

Language: Английский

---

Broad-Scope Rh-Catalyzed Inverse-Sonogashira Reaction Directed by Weakly Coordinating Groups

ACS Catalysis, Journal Year: 2018, Volume and Issue: 8(3), P. 2166 - 2172

Published: Jan. 30, 2018

We report the alkynylation of C(sp2)-H bonds with bromoalkynes (inverse-Sonogashira reaction) directed by synthetically useful ester, ketone, and ether groups under rhodium catalysis. Other less common directing such as amine, thioether, sulfoxide, sulfone, phenol carbamate are also suitable groups. Mechanistic studies indicate that reaction proceeds a turnover-limiting C-H activation step via an electrophilic-type substitution.

Language: Английский

---

Recent advances in Rh(iii)/Ir(iii)-catalyzed C–H functionalization/annulation via carbene migratory insertion

Organic & Biomolecular Chemistry, Journal Year: 2021, Volume and Issue: 19(7), P. 1438 - 1458

Published: Jan. 1, 2021

The review highlighted diverse annulations, including nitrogen, oxygen, sulfur heterocycles and carbocylizations via Rh(iii)/Ir(iii)-catalyzed C–H functionalization/annulation with various arene carbene precursors.

Language: Английский

---

Rh(III)-Catalyzed and Solvent-Controlled Chemoselective Synthesis of Chalcone and Benzofuran Frameworks via Synergistic Dual Directing Groups Enabled Regioselective C–H Functionalization: A Combined Experimental and Computational Study

ACS Catalysis, Journal Year: 2018, Volume and Issue: 8(10), P. 9508 - 9519

Published: Sept. 5, 2018

By virtue of a synergistically dual-directing-group (the O–NHAc part and the hydroxyl group)-assisted strategy, efficient practical Rh(III)-catalyzed regioselective redox-neutral C–H functionalization diverse N-phenoxyacetamides with propargyl alcohols has been realized, which led to divergent synthesis privileged benzofuran chalcone frameworks in solvent-controlled chemoselective manner. Experimental computational studies reveal that formation hydrogen bonding between dual directing groups subsequent coordination interaction group Rh(III) catalyst play decisive role promoting migratory insertion alkyne moiety. Thereafter, two switchable reaction pathways, respectively involve tandem β–H elimination/hydrogen transfer/oxidative addition/C–O bond reductive elimination/oxidation (for low-polar solvents: path I–Ia via RhIII–RhI–RhIII pathway) oxidative addition/β–H transfer/protonolysis high-polar II–IIb RhIII–RhV–RhIII pathway), are followed deliver corresponding products excellent chemoselectivity. Taken together, our results presented here not only give an expansion area O–NHAc-directed activations but also provide rational basis for future development synergistic DGs-enabled reactions.

Language: Английский

---

Rhodium(III)‐Catalyzed Enantio‐ and Diastereoselective C−H Cyclopropylation of N‐Phenoxylsulfonamides: Combined Experimental and Computational Studies

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(7), P. 2890 - 2896

Published: Dec. 9, 2019

Cyclopropane rings are a prominent structural motif in biologically active molecules. Enantio- and diastereoselective construction of cyclopropanes through C-H activation arenes coupling with readily available cyclopropenes is highly appealing but remains challenge. A dual directing-group-assisted strategy was used to realize mild redox-neutral RhIII -catalyzed cyclopropylation N-phenoxylsulfonamides enantioselective, diastereoselective, regioselective fashion cyclopropenyl secondary alcohols as cyclopropylating reagent. Synthetic applications demonstrated highlight the potential developed method. Integrated experimental computational mechanistic studies revealed that reaction proceeds via RhV nitrenoid intermediate, Noyori-type outer sphere concerted proton-hydride transfer from alcohol Rh=N bond produces observed trans selectivity.

Language: Английский

---

Co(III), Rh(III) & Ir(III)‐Catalyzed Direct C−H Alkylation/Alkenylation/Arylation with Carbene Precursors

Chemistry - An Asian Journal, Journal Year: 2021, Volume and Issue: 16(5), P. 443 - 459

Published: Jan. 15, 2021

Metal carbenes play a pivotal role in transition-metal-catalyzed synthetic transfer reactions. The metal carbene is generated either from diazo compound through facile extrusion of N2 with catalyst or situ other sources like triazoles, pyriodotriazoles, sulfoxonium ylides and iodonium-ylide. On the hand, Co(III), Rh(III) & Ir(III)-catalyzed C-H functionalizations have been well established as key step to enable construction various transformations. Interestingly, recent years, merging these two concepts activation migratory insertion gained much attention, particular group 9 metal-catalyzed arene precursors via insertion. In this review, we summarize advances direct alkylation/alkenylation/arylation also discuss intermediates within catalytic cycles.

Language: Английский

---

Efficient Synthesis of Arylated Furans by a Sequential Rh‐Catalyzed Arylation and Cycloisomerization of Cyclopropenes

Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 57(6), P. 1712 - 1716

Published: Dec. 24, 2017

A novel and efficient strategy for the synthesis of arylated furans was successfully developed by a RhIII -catalyzed coupling N-phenoxyacetamides cyclopropenyl esters. Mechanistic investigation reveals that are formed via arylation esters followed cycloisomerization.

Language: Английский

---