N-Heterocyclic Carbene Complexes in C-H Activation Reactions

Abstract

In this contribution, we provide a comprehensive overview of C-H activation methods promoted by NHC-transition metal complexes, covering the literature since 2002 (the year of the first report on metal-NHC-catalyzed C-H activation) through June 2019, focusing on both NHC ligands and C-H activation methods. This review covers C-H activation reactions catalyzed by group 8 to 11 NHC-metal complexes. Through discussing the role of NHC ligands in promoting challenging C-H activation methods, the reader is provided with an overview of this important area and its crucial role in forging carbon-carbon and carbon-heteroatom bonds by directly engaging ubiquitous C-H bonds.

Figure 1.. Structures of the Most Common NHCs Used in C–H Activation Reactions

Scheme 1.

Pd–NHC Catalyzed Aldehyde Directed C(sp²)–H Arylation by Cetinkaya

Scheme 2.

Pd–NHC Catalyzed Aldehyde Directed C(sp²)–H Arylation using Six-Membered NHC Ligands by Cetinkaya

Scheme 3.

Pd–NHC Catalyzed Aldehyde Directed C(sp²)–H Arylation using Benzimidazolium NHC Ligands by Cetinkaya

Scheme 4.

Pd–NHC Catalyzed Aldehyde Directed C(sp²)–H Arylation using Imidazolinium NHC Ligands by Cetinkaya

Scheme 5.

Pd–NHC Catalyzed Intramolecular Non-Directed C(sp²)–H/C(sp²)–X Activation by Fagnou

Scheme 6.

Pd–NHC Catalyzed Intramolecular Non-Directed C(sp²)–H/C(sp²)–X Activation by Sefkov

Scheme 7.

Pd–NHC Catalyzed Direct C3–H Arylation of Indole by Sames

Scheme 8.

Pd–NHC Catalyzed Direct C–H Arylation of Azoles by Sames

Scheme 9.

Pd–NHC Catalyzed Direct C–H Arylation of Indoles and Pyrroles by Sanford

Scheme 10.

Pd–NHC Catalyzed Direct C–H Arylation of Furans, Thiophenes and Thiazoles by Özdemir

Scheme 11.

Pd–NHC Catalyzed Direct C–H Arylation of Furans, Thiophenes and Thiazoles by Akkoc

Scheme 12.

Pd–NHC Catalyzed Direct C–H Arylation of Furans, Thiophenes and Thiazoles by Akkoc

Scheme 13.

Pd–NHC Catalyzed Direct C–H Arylation of Furans, Thiophenes and Thiazoles using 6-Membered NHC Ligands by Cetinkaya

Scheme 14.

Pd–NHC Catalyzed Direct C–H Arylation of Furans and Thiophenes by Akkoc

Scheme 15.

Pd–NHC Catalyzed Direct C–H Arylation of Furans, Thiophenes and Pyrroles by Lee

Scheme 16.

Pd–NHC Catalyzed Direct C–H Arylation of Thiophenes and Imidazopyridines by Nolan

Scheme 17.

Pd–NHC Catalyzed Direct C–H Arylation of Furans and Thiophenes by Grisi

Scheme 18.

Pd–NHC Catalyzed Direct C–H Arylation of Benzo[b]Furans by Shao

Scheme 19.

Pd–NHC Catalyzed Direct C–H Arylation of Thiophenes by Shao

Scheme 20.

Pd–H Arylation of Pyrroles by Doucet

Scheme 21.

Pd–NHC Catalyzed Direct C–H Arylation of Pyrrole using Indazolin-3-ylidene Complexes by Huynh

Scheme 22.

Pd–H Arylation of Pyrrole using Benzimidazolin-2-ylidene Complexes by Huynh

Scheme 23.

Pd–NHC Catalyzed Direct C–H Arylation of Pyrroles by Yigit

Scheme 24.

Pd–H Arylation of Pyrroles by Özdemir

Scheme 25.

Pd–NHC Catalyzed Direct C–H Arylation of Pyrroles by Özdemir

Scheme 26.

Pd–NHC Catalyzed Direct C5–H Arylation of Imidazoles by Sames

Scheme 27.

Pd–NHC Catalyzed Direct C–H Arylation of Benzothiazole by Özdemir

Scheme 28.

Pd–NHC Catalyzed Direct C–H Arylation of Benzothiazole and Benzoxazole by Arslan

Scheme 29.

Pd–NHC Catalyzed Direct C–H Arylation of Benzothiazole by Özdemir

Scheme 30.

Pd–NHC Catalyzed Direct C–H Arylation of Benzothiazole by Özdemir

Scheme 31.

Pd–NHC Catalyzed Direct C–H Arylation of Benzothiazole and Benzoxazole by Özdemir

Scheme 32.

Pd–NHC Catalyzed Direct C–H Arylation of Thiazole by Özdemir

Scheme 33.

Pd–NHC Catalyzed Direct C–H Arylation of Oxazoles by Hoarau

Scheme 34.

Pd–NHC Catalyzed Direct C–H Arylation of Oxazoles by Shao

Scheme 35.

Pd–NHC Catalyzed Direct C–H Benzylation of Oxazoles by Shao

Scheme 36.

Pd–NHC Catalyzed Direct C–H Arylation of Benzoxazoles by Yang

Scheme 37.

Pd–NHC Catalyzed Direct C–H Arylation of Benzoxazoles by Gandhi

Scheme 38.

Pd–NHC Catalyzed Direct C–H Arylation of Benzoxazoles by Li

Scheme 39.

Pd–NHC Catalyzed Direct C–H Arylation of Benzoxazoles by Yang

Scheme 40.

Pd–NHC Catalyzed Direct C–H Arylation of Benzoxazoles by Yang

Scheme 41.

Pd–NHC Catalyzed Direct C–H Arylation of Benzoxazoles by Yang

Scheme 42.

Pd–NHC Catalyzed Direct C5–H Arylation of Imidazoles by Lee

Scheme 43.

Pd–NHC Catalyzed Direct C–H Arylation of Imidazoles by Lee

Scheme 44.

Pd–NHC Catalyzed Direct C–H Arylation of Imidazoles by Shao

Scheme 45.

Pd–NHC Catalyzed Direct C3–H Arylation of Imidazo[1,2-a]pyridines by Shao

Scheme 46.

Pd–NHC Catalyzed Direct C5–H Arylation of Imidazoles by Huynh

Scheme 47.

Pd–NHC Catalyzed Direct C5–H Arylation of Imidazoles by Liu

Scheme 48.

Pd–NHC Catalyzed Direct C–H Arylation of Imidazoles, Thiazoles, Isoxazoles, Pyrazoles and Triazoles by Liu

Scheme 49.

Pd–NHC Catalyzed Direct C–H Arylation of Pentafluorobenzene by Huynh

Scheme 50.

Pd–NHC Catalyzed Direct C–H Arylation of Pentafluorobenzene by Huynh

Scheme 51.

Pd–NHC Catalyzed Direct C–H Arylation of Pentafluorobenzene by Huynh

Scheme 52.

Pd–NHC Catalyzed Synthesis of Benzofurans by Hydroxyl Directed C(sp²)–H Activation by Liu

Scheme 53.

Pd–NHC Catalyzed Hydroxyl Directed C(sp²)–H Oxidative Annulation by Lam

Scheme 54.

Pd–NHC Catalyzed Carboxylate Directed C(sp²)–H Arylation/Decarboxylation by Larrosa

Scheme 55.

Pd–NHC Catalyzed Oxidation/Carboxylate Directed C(sp²)–H Arylation/Decarboxylation by Larrosa

Scheme 56.

Pd–NHC Catalyzed Sulfoxide Directed C(sp²)–H Arylation by Colobert

Scheme 57.

Pd–NHC Catalyzed C(sp²)–H Bromination by Arnold and Sanford

Scheme 58.

Pd–NHC Catalyzed C(sp²)–H Acetoxylation by Cardenas

Scheme 59.

Pd–NHC Catalyzed C(sp²)–H Acetoxylation and Bromination by Choudhury

Scheme 60.

Pd–NHC Catalyzed C(sp²)–H Acetoxylation and Halogenation by Choudhury

Scheme 61.

Pd–NHC Catalyzed C(sp²)–H Halogenation by Choudhury

Scheme 62.

Pd–NHC Catalyzed C(sp²)–H Acetoxylation by Wendt

Scheme 63.

Pd–NHC Catalyzed Intramolecular C(Acyl)–H/C(sp²)–Cl Arylation by Martin

Scheme 64.

Pd–NHC Catalyzed C–H Oxidation of Methane by Strassner

Scheme 65.

Pd–NHC Catalyzed C–H Oxidation of Methane by Strassner

Scheme 66.

Pd–NHC Catalyzed C–H Oxidation of Methane by Strassner

Scheme 67.

Pd–NHC Catalyzed C–H Oxidation of Methane using Pyrimidine-Functionalized NHC Ligands by Strassner

Scheme 68.

Proposed Mechanism in Pd–NHC Catalyzed C–H Oxidation of Methane by Strassner

Scheme 69.

Pd–NHC Catalyzed Non-Directed Benzylic C–H/C–X Arylation by Wu

Scheme 70.

Pd–NHC Catalyzed Asymmetric C(sp³)–H/C–X Arylation by Kündig

Scheme 71.

Synthesis of Indolines by Pd–NHC Catalyzed Asymmetric C(sp³)–H/C–X Arylation by Kündig

Scheme 72.

Synthesis of Functionalized Fused Indolines by Pd–NHC Catalyzed Asymmetric C(sp³)–H/C–X Arylation by Kündig

Scheme 73.

Pd–NHC Catalyzed Regiodivergent Asymmetric C(sp³)–H/C–X Arylation by Kündig

Scheme 74.

Pd–NHC Catalyzed Asymmetric C(sp³)–H/C–X Arylation and Application to the Synthesis of (Nor)illudalanes by Baudoin

Scheme 75.

Pd–NHC Catalyzed Benzylic C(sp³)–H/C–X Acylation by Cramer

Scheme 76.

Pd–NHC Catalyzed Tandem Aminopalladation/Benzylic C(sp³)–H Activation by Yang

Scheme 77.

Pd–NHC Catalyzed Intermolecular Benzylic C(sp³)–H/C–X Arylation by Shao

Scheme 78.

Pd–NHC Catalyzed Amide Directed C(sp³)–H Alkynylation by Yu

Scheme 79.

Pd–NHC Catalyzed Amide Directed C(sp³)–H Arylation of Piperidines by Yu

Scheme 80.

Pd–NHC Catalyzed C(sp³)–H Acetoxylation of Unactivated Methylenes by Hou

Scheme 81.

Pd–NHC Catalyzed Benzylic C(sp³)–H Chlorination by Kraft

Scheme 82.

Pd–NHC Catalyzed Allylic C(sp³)–H Activation/Allylation of Oxindoles by Yang

Scheme 83.

Pd–NHC Catalyzed C–H/C–D Exchange using D₂O by Jung

Scheme 84.

Pd–NHC Catalyzed C–H/C–D Exchange using CF₃CO₂D by Jung

Scheme 85.

Pd–NHC Catalyzed Hydroarylation of Alkynes by Strassner

Scheme 86.

Pt–NHC Catalyzed C–H Activation of Methane by Strassner

Scheme 87.

Pt-NHC Catalyzed C(sp²)–H Borylation by Chatani

Scheme 88.

Proposed Mechanism for the Pt-NHC Catalyzed C(sp²)–H Borylation

Scheme 89.

Solvent Dependent C–H Activation in [(ItBu)Rh(coe)Cl]₂ Complex by Nolan

Scheme 90.

Intramolecular C–H Activation via a Rh–NHC Complex by Bergman and Ellman

Scheme 91.

Intermolecular C–H Activation via a Rh–NHC Complex by Bergman and Ellman

Scheme 92.

C(sp²)–H/C–X Arylation Catalyzed by NHC/Phosphine Rh Complexes by Chang

Scheme 93.

Rh–NHC Catalyzed C(sp²)–H/C–X C8–Arylation of Quinolines by Chang

Scheme 94.

Rh–NHC Catalyzed Double C(sp²)–H Activation/Hydroarylation by Chang

Scheme 95.

Rh–NHC Catalyzed Double Triazole Directed C(sp²)–H Olefination by Wu

Scheme 96.

Rh–NHC Catalyzed Oxazoline Directed C(sp²)–H/C–O Arylation by Chatani

Scheme 97.

Rh–NHC Catalyzed Hydroxyl Directed C(sp²)–H Carboxylation by Li

Scheme 98.

Rh–NHC Catalyzed Pyridine Directed C(sp²)–H Borylation by Crudden

Scheme 99.

Rh–NHC Catalyzed Pyridine Directed C(sp²)–H Borylation by Basle

Scheme 100.

Rh–NHC Catalyzed Pyridine Directed C(sp²)–H Borylation by Wang

Scheme 101.

Rh–NHC Catalyzed C(Acyl)–H Activation/Allene Addition by Sato

Scheme 102.

Two-Fold C(sp²)–H Annulation via Rh–NHCs by Choudhury

Scheme 103.

C(sp²)–H Annulation of Pyridine via Rh–NHCs by Choudhury

Scheme 104.

Vinylic C(sp²)–H Annulation via Rh–NHCs by Choudhury

Scheme 105.

C(sp²)–H Annulation of Chelating Heterocycles via Rh–NHCs by Choudhury

Scheme 106.

Proposed Mechanism for C(sp²)–H Annulation via Rh–NHCs by Choudhury

Scheme 107.

C(sp²)–H/C–N Annulation via Rh–NHCs by Choudhury

Scheme 108.

C(sp²)–H Annulation via Abnormal Rh–NHCs by Choudhury

Scheme 109.

C(sp²)–H Annulation via Thiazolium Rh–NHCs by Choudhury

Scheme 110.

Two-Fold C(sp²)–H/C–H Arylation via Rh–NHCs by You

Scheme 111.

Rh–NHC Catalyzed Intramolecular C(sp³)–H Cyclopropanation by Sato

Scheme 112.

Rh–NHC Catalyzed Ketone α-Alkylation by Dong

Scheme 113.

Rh–NHC Catalyzed Benzylic C(sp³)–H Arylation by Glorius

Scheme 114.

Rh–NHC Catalyzed Vinylic C–H/C–D Exchange by Oro

Scheme 115.

Rh–NHC Catalyzed Vinylic Selective C–H/C–D Exchange by Oro

Scheme 116.

Time Dependent C–H Activation in [(ItBu)Ir(coe)Cl]₂ Complex by Nolan

Scheme 117.

Intramolecular C–H Activation in [(NHC)IrCp*Cl₂] Complex by Peris

Scheme 118.

Intramolecular C(sp²)–H and C(sp³)–H Activation in [(NHC)IrCp*I₂] Complexes by Peris

Scheme 119.

Ir–NHC Catalyzed C(sp²)–H Borylation by Herrmann

Scheme 120.

Ir–NHC Catalyzed C(sp²)–H Borylation of Disubstituted Benzenes by Herrmann

Scheme 121.

Ir–NHC Catalyzed C(sp²)–H Borylation of Heterocycles by Chatani

Scheme 122.

Ir–NHC Catalyzed Pyridine-Directed C(sp²)–H Silylation by Mashima

Scheme 123.

Ir–NHC Catalyzed C(sp²)–H Silylation of Arenes by Oro

Scheme 124.

Ir–NHC Catalyzed Intramolecular C(sp³)–H Activation/Cyclization by Sames

Scheme 125.

Ir–NHC Mediated C–H/C–D Exchange by Powell

Scheme 126.

Ir–NHC Catalyzed C–H/C–D Exchange by Kerr

Scheme 127.

Ir–NHC Catalyzed C–H/C–D Exchange in Niclosamide by Kerr

Scheme 128.

C–H/C–D Exchange Catalyzed by Neutral Ir–NHC Complexes by Kerr

Scheme 129.

Ir–NHC Catalyzed C–H/C–D Exchange in Benign Solvents by Kerr

Scheme 130.

Ir–NHC Catalyzed Vinylic C–H/C–D Exchange by Kerr

Scheme 131.

Ir–NHC Catalyzed C–H/C–D Exchange in Aryl Sulfonamides by Kerr

Scheme 132.

Ir–NHC Catalyzed C–H/C–D Exchange in Aryl Esters by Kerr

Scheme 133.

C–H/C–D Exchange Catalyzed by Cationic [(NHC)Ir(cod)(py)] Complexes by Kerr

Scheme 134.

Ir–NHC Catalyzed C–H/C–D Exchange in Aryl Tetrazoles under Basic Conditions by Kerr

Scheme 135.

Ir–NHC Catalyzed C–H/C–D Exchange in N-Heterocycles by Kerr

Scheme 136.

Ir–NHC Catalyzed Formyl C–H/C–D Exchange in Aldehydes by Kerr

Scheme 137.

Ir–NHC Catalyzed C(sp³)–H/C–D Exchange in Amines by Kerr

Scheme 138.

Ru–NHC Catalyzed Direct C(sp²)–H/C–Br Arylation by Dixneuf

Scheme 139.

Ru–NHC Catalyzed Direct C(sp²)–H/C–Cl Arylation by Özdemir

Scheme 140.

Ru–NHC Direct Catalyzed C(sp²)–H/C–Cl Arylation by Bruneau

Scheme 141.

Ru–NHC Catalyzed Direct C(sp2)–H/C–Cl Arylation by Özdemir

Scheme 142.

Ru–NHC Catalyzed Monoselective C(sp²)–H/C–Cl Arylation by Özdemir

Scheme 143.

Ru–NHC Catalyzed Direct C(sp²)–H/C–X Arylation by Peris

Scheme 144.

Ru–NHC Catalyzed Direct C(sp²)–H/C–X Arylation using Pyrene Ligands by Peris

Scheme 145.

Ru–NHC Catalyzed Direct C(sp²)–H/C–X Arylation/Oxidation using Bimetallic Complexes by Peris

Scheme 146.

Ru–NHC Catalyzed Direct C(sp²)–H/C–Cl Benzylation and Alkylation of Isoquinolione by Ong

Scheme 147.

Ru–NHC Catalyzed Imine Directed C(sp²)–H Activation/Carbocyclization by Zhao

Scheme 148.

Ru–NHC Catalyzed Amide Directed C(sp²)–H Activation/Hydroarylation by Zhao

Scheme 149.

Oxidative Two-Fold C(sp²)–H Annulation via Ru–NHCs by Wang

Scheme 150.

Ru–NHC Catalyzed Ketone α-Alkylation by Glorius

Scheme 151.

Ru–NHC Catalyzed Benzylic C(sp³)–H Oxidation by Choudhury

Scheme 152.

Fe–NHC Catalyzed C(sp²)–H Borylation of Furans and Thiophenes by Tatsumi

Scheme 153.

Fe–NHC Catalyzed Imine Directed C(sp²)–H Alkylation of Indoles by Yoshikai

Scheme 154.

Asymmetric Fe–NHC Catalyzed Imine Directed C(sp²)–H Alkylation of Indoles by Ackermann

Scheme 155.

Fe–NHC Porphyrin Catalyzed Intramolecular C(sp³)–H Amination by Che

Scheme 156.

Esterification of Benzylic C(sp³)–H Bonds by Sun

Scheme 157.

Co–NHC Catalyzed Pyridine Directed C(sp²)–H/C–O Arylation by Ackermann

Scheme 158.

Co–NHC Catalyzed Pyridine Directed C(sp²)–H/C–Cl Arylation by Ackermann

Scheme 159.

Co–NHC Catalyzed Amide Directed C(sp²)–H/C–Cl Arylation by Ackermann

Scheme 160.

Co–NHC Catalyzed Oxazoline Directed C(sp²)–H/C–Cl Arylation by Ackermann

Scheme 161.

Co–NHC Catalyzed Pyridine Directed C(sp²)–H/C–O Alkenylation by Ackermann

Scheme 162.

Co–NHC Catalyzed Pyridine Directed C(sp²)–H/C–O Alkenylation using Triazolylidene Ligands by Ackermann

Scheme 163.

Co–NHC Catalyzed C(sp²)–H Alkylation by Yoshikai

Scheme 164.

Intramolecular Co–NHC Catalyzed C(sp²)–H Alkylation by Yoshikai

Scheme 165.

Co–NHC Catalyzed Alkene Isomerization/C(sp²)–H Alkylation by Yoshikai

Scheme 166.

Co–NHC Catalyzed Imine Directed C(sp²)–H/C–Cl Arylation by Yoshikai

Scheme 167.

Co–NHC Catalyzed Imine Directed C(sp²)–H/C–X Alkylation by Yoshikai

Scheme 168.

Co–NHC Catalyzed Pyridine Directed C(sp²)–H Addition to Aldimines by Yoshikai

Scheme 169.

Co–NHC Catalyzed Pyridine Directed C(sp²)–H Addition to Aziridines by Yoshikai

Scheme 170.

Co–NHC Catalyzed Imine Directed C(sp²)–H/C–O Alkenylation by Yoshikai

Scheme 171.

Co–NHC Catalyzed Pyridine and Imine Directed C(sp²)–H/C–O Methylation by Yoshikai

Scheme 172.

Co–NHC Catalyzed Pivalophenone Imine Directed C(sp²)–H/C–Br Alkylation by Yoshikai

Scheme 173.

Co–NHC Catalyzed Pivalophenone Imine Directed C(sp²)–H/C–O Alkenylation by Yoshikai

Scheme 174.

Co–NHC Catalyzed Imine Directed C(sp²)–H/C(sp³)–H Coupling by Yoshikai

Scheme 175.

Co–NHC Catalyzed Imine Directed C(sp²)–H/ Tandem C–C Coupling by Yoshikai

Scheme 176.

Co–NHC Catalyzed C(sp²)–H/Decarboxylative Arylation by Li

Scheme 177.

Ni–NHC Catalyzed C4 Selective C(sp²)–H Alkylation of Pyridines by Nakao

Scheme 178.

Ni–NHC Catalyzed C4 Selective C(sp²)–H Alkenylation of Pyridines by Ong

Scheme 179.

Ni–NHC Catalyzed Switchable C4 Selective C(sp²)–H Alkylation of Pyridines by Ong

Scheme 180.

Ni–NHC Catalyzed C2 Selective C(sp²)–H Alkylation of Heterocycles by Nakao

Scheme 181.

Ni–NHC Catalyzed C2 Linear Selective C(sp²)–H Alkylation of Heterocycles by Hartwig

Scheme 182.

Ni–NHC Catalyzed C(sp²)–H Functionalization of Heterocycles with Allenes by Ackermann

Scheme 183.

Ni–NHC Catalyzed Switchable C2 Selective C(sp²)–H Alkylation of Heterocycles by Ong

Scheme 184.

Ni–NHC Catalyzed Switchable C2 Selective C(sp²)–H Isomerization/Alkylation of Heterocycles by Ong

Scheme 185.

Ni–NHC Catalyzed Regiodivergent C(sp²)–H Alkenylation of Imidazo[1,5-a]pyridine by Ong

Scheme 186.

Ni–NHC Catalyzed C5 Selective C(sp²)–H Alkenylation of Imidazo[1,5-a]pyridine by Ong

Scheme 187.

Ni–NHC Catalyzed C2 Selective C(sp²)–H Alkenylation of Heterocycles with Cyclodienes by Ong

Scheme 188.

Abnormal Ni–NHC Catalyzed C2 Selective Alkylation of Benzoxazoles by Mandal

Scheme 189.

Ni–NHC Catalyzed p-Selective Alkylation of Benzamides and Ketones by Nakao

Scheme 190.

Ni–NHC Catalyzed Remote Alkylation of Anilides by Nakao

Scheme 191.

Ni–NHC Catalyzed C6 Selective Alkylation of Benzofurans by Nakao

Scheme 192.

Ni–NHC Catalyzed p-Selective Alkylation of Sulfonylarenes by Nakao

Scheme 193.

Intramolecular Ni–NHC Catalyzed C(sp²)–H Annulation of Pyridones by Cramer

Scheme 194.

Asymmetric Ni–NHC Catalyzed C(sp²)–H Annulation of Pyridones by Cramer

Scheme 195.

Asymmetric Ni–NHC Catalyzed C(sp²)–H Annulation of Indoles by Cramer

Scheme 196.

Intramolecular Ni–NHC Catalyzed C(sp²)–H Annulation by Sames

Scheme 197.

Ni–NHC Catalyzed C(sp²)–H Alkenylation of Acidic C–H Bonds by Montgomery

Scheme 198.

Ni–NHC Catalyzed Amide Directed C(sp²)–H Oxidative Annulation by Chatani

Scheme 199.

Ni–NHC Catalyzed Amide Directed C(sp²)–H Alkylation by Chatani

Scheme 200.

Ni–NHC Catalyzed Direct C(sp²)–H/C–I Arylation of Azoles by Ritleng

Scheme 201.

Ni–NHC Catalyzed Direct C(sp²)–H/C–O Arylation of Azoles by Ong

Scheme 202.

Ni–NHC Catalyzed C(sp²)–H Borylation by Chatani

Scheme 203.

Ni–NHC Catalyzed C(Acyl)–H Amidation by Dong

Scheme 204.

Ni–NHC Catalyzed C(Acyl)–H Arylation/Alkylation by Ge

Scheme 205.

Cu–NHC Catalyzed C(sp²)–H Carboxylation by Hou

Scheme 206.

Cu–NHC Catalyzed C(sp²)–H Carboxylation by Nolan

Scheme 207.

Cu–NHC Catalyzed C(sp²)–H Carboxylation using Triazolylidine Complexes by Hou

Scheme 208.

Cu–NHC Catalyzed C(sp²)–H Carboxylation using pH-Responsive Ligands by Li

Scheme 209.

Cu–NHC Catalyzed C(sp²)–H Carboxylation using Bifunctional Ligands by Hong

Scheme 210.

Cu–NHC Catalyzed C(sp²)–H Deprotonative ortho-Carboxylation by Hou

Scheme 211.

Cu–NHC/Pd–NHC Catalyzed C(sp²)–H/C–X Arylation by Cazin

Scheme 212.

Cu–NHC Catalyzed C(sp²)–H Alkenylation and Allylation by Chang

Scheme 213.

Enantioselective Cu–NHC Catalyzed C(sp²)–H Allylation by Sawamuara

Scheme 214.

Cu–NHC Catalyzed C(sp²)–H Amidation by Chang

Scheme 215.

Cu–NHC Catalyzed C(sp²)–H Oxidative Thiolation by Fukuzawa

Scheme 216.

Cu–NHC Catalyzed C(sp²)–H/C–I Arylation of Caffeine by Ong

Scheme 217.

Cu–NHC Catalyzed C(sp)–H Carboxylation by Zhang

Scheme 218.

Cu–NHC Catalyzed C(sp)–H Carboxylation/Allylation by Lu

Scheme 219.

Enantioselective Cu–NHC Catalyzed C(sp)–H Allylation by Sawamura

Scheme 220.

Intermolecular Cu–NHC Catalyzed C(sp³)–H Alkylation by Perez

Scheme 221.

Ag–NHC Catalyzed C(sp)–H Carboxylation by Zhang

Scheme 222.

Au–NHC Catalyzed C(sp²)–H Carboxylation by Nolan

Scheme 223.

Au–NHC Catalyzed C(sp²)–H Alkylation by Perez

Scheme 224.

Au–NHC Catalyzed Oxidative C(sp³)–H Cyanation of Amines by Che

Scheme 225.

Au–NHC Catalyzed C(sp³)–H Alkylation by Perez