Ligand-Enabled Meta-C–H Alkylation and Arylation Using a Modified Norbornene

Abstract

2-Carbomethoxynorbornene is identified as a more effective transient mediator to promote a Pd(II)-catalyzed meta-C(sp2)–H alkylation of amides with various alkyl iodides as well as arylation with previously incompatible aryl iodides. The use of a tailor-made quinoline ligand is also crucial for this reaction to proceed.

Palladium(II)‐Initiated Catellani‐Type Reactions

“…[16] Whereas ortho-selective C À Hf unctionalization reactions of arenes have been well developed, meta-selective CÀHf unctionalization remains ac hallenge. [19] As eparate approach using Pd II /NBE cooperative catalysis was developed by the groups of Yu,Dong, Zhao,Shi, Ferreira, and others, [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] who drew inspiration from the Catellani reaction. [19] As eparate approach using Pd II /NBE cooperative catalysis was developed by the groups of Yu,Dong, Zhao,Shi, Ferreira, and others, [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] who drew inspiration from the Catellani reaction.…”

“…[21] Later on, they realized the meta C À Ha lkylation of benzylsulfonamide (sulfonamide as an ortho-directing group) by using Yu mediator 52 and simple isoquinoline as the ligand, generating the desired meta-alkylated products 54 in 45-72 % yield (Scheme 11 c). [21] Later on, they realized the meta C À Ha lkylation of benzylsulfonamide (sulfonamide as an ortho-directing group) by using Yu mediator 52 and simple isoquinoline as the ligand, generating the desired meta-alkylated products 54 in 45-72 % yield (Scheme 11 c).…”

“…[21] In 2016, Zhao and co-workers reported as elective meta arylation of b-arylethylamine derivatives 60 with abidentate oxalyl-amide-based directing group and simple NBE as the mediator (Scheme 13). [21] In 2016, Zhao and co-workers reported as elective meta arylation of b-arylethylamine derivatives 60 with abidentate oxalyl-amide-based directing group and simple NBE as the mediator (Scheme 13).…”

meta‐C−H Bromination on Purine Bases by Heterogeneous Ruthenium Catalysis

“…[3b,c] Aplethora of arene C À Hf unctionalizations have been accomplished by proximity-induced C À Ha ctivation through chelation assistance. [4] In sharp contrast to ortho-CÀHf unctionalizations,r emote [5] CÀHt ransformations continue to be scarce, [6] with notable recent progress realized with the aid of ruthenium catalysis. [7] Despite these considerable advances, [5] ruthenium-catalyzed meta-selective C À Hf unctionalizations have thus far been restricted to homogeneous catalysis,r endering catalyst reuse challenging, while at the same time leading to significant quantities of undesired metal impurities in the target products.W ithin our program on ruthenium-catalyzed C À Ha ctivation, [8] we have now developed the first heterogeneous [9] catalyst for meta-CÀHh alogenations, [10] on which we report herein.…”

Palladium-Catalyzed Double C–H Functionalization of Arenes at the Positions <i>ortho</i> and <i>meta</i> to Their Directing Group: Concise Synthesis of Benzocyclobutenes

“…The norbornene-mediated C-H functionalization of arenes has been extended to the direct functionalization of indoles 18,19) and the meta-selective C-H functionalization of arenes and heteroaerenes. [20][21][22][23][24] However, only one functional group can be introduced at the meta position using these reactions, thus the development of a more efficient approach is still highly desired.…”