Accessing Remote meta‐ and para‐C(sp²)−H Bonds with Covalently Attached Directing Groups

Angewandte Chemie International Edition, Год журнала: 2018, Номер 58(32), С. 10820 - 10843

Опубликована: Ноя. 29, 2018

Directing group assisted ortho-C-H activation has been known for the last few decades. In contrast, extending same approach to achieve of distal meta- and para-C-H bonds in aromatic molecules remained elusive a long time. The main challenge is conception macrocyclic transition state, which needed anchor metal catalyst close target bond. Judicious modification chain length, tether linkage, nature catalyst-coordinating donor atom led number successful studies years. This Review compiles significant achievements made this field both para-selectivity using covalently attached directing groups, are systematically classified on basis their mode covalent attachment substrate as well chemical nature. aims create more heuristic recognizing suitability groups use future organic transformations.

Язык: Английский

---

Catalytic alkylation of unactivated C(sp³)–H bonds for C(sp³)–C(sp³) bond formation

Chemical Society Reviews, Год журнала: 2019, Номер 48(18), С. 4921 - 4942

Опубликована: Янв. 1, 2019

This review summarizes recent advancements in catalytic direct transformation of unactivated C(sp³)–H bonds into C(sp³)–C(sp³) bonds.

Язык: Английский

---

Uses of K₂S₂O₈ in Metal-Catalyzed and Metal-Free Oxidative Transformations

ACS Catalysis, Год журнала: 2018, Номер 8(6), С. 5085 - 5144

Опубликована: Апрель 13, 2018

Carbon–carbon/carbon–heteroatom bond formation via oxidative transformations is a heavily explored topic at the frontier of chemistry. Potassium persulfate (K2S2O8) has emerged as cost-effective, suitable inorganic oxidant for wide array transformations, ranging from laboratory experiments to industrial processes. The current review provides comprehensive coverage aided with K2S2O8 in presence or absence transition-metal catalyst, critical assessment results, and underlying mechanisms. Organic chemists may find this be useful guide expedient synthesis new chemical entities, formulate mechanistic manifolds involving sulfate radical anion, design novel transformations. A detailed understanding unsolved mechanisms could further enrich field.

Язык: Английский

---

Increasing Catalyst Efficiency in C−H Activation Catalysis

Angewandte Chemie International Edition, Год журнала: 2017, Номер 57(9), С. 2296 - 2306

Опубликована: Дек. 5, 2017

Abstract C−H activation reactions with high catalyst turnover numbers are still very rare in the literature and 10 mol % is a common loading this field. We offer representative overview of efficient catalysis to highlight neglected aspect development inspire future effort towards more activation. Examples ranging from palladium catalysis, Cp*Rh III ‐ Cp*Co ‐catalysis, borylation silylation methane presented. In these reactions, up tens thousands turnovers have been observed.

Язык: Английский

---

Access to the meta position of arenes through transition metal catalysed C–H bond functionalisation: a focus on metals other than palladium

Chemical Society Reviews, Год журнала: 2017, Номер 47(1), С. 149 - 171

Опубликована: Окт. 26, 2017

The elaboration of simple arenes in order to access more complex substitution patterns is a crucial endeavor for synthetic chemists, given the central role that aromatic rings play all manner important molecules. Classical methods are now routinely used alongside stoichiometric organometallic approaches and, most recently, transition metal catalysis range methodologies available elaborate arene C-H bonds. Regioselectivity an consideration when selecting method those available, it arguably target meta position fewest number. rapid development metal-catalysed bond functionalisation over last few decades has opened new possibilities meta-selective through diverse reactivity metals and their compatibility with wide directing groups. pace discovery such processes grown rapidly five years particular purpose this review examine these but doing so place focus on other than palladium, specific contributions which have been very recently reviewed elsewhere. It hoped will serve highlight reader breadth current strategies mechanisms tackle challenge, may inspire further progress field.

Язык: Английский

---

Sulfoxonium Ylides as a Carbene Precursor in Rh(III)-Catalyzed C–H Acylmethylation of Arenes

Organic Letters, Год журнала: 2017, Номер 19(19), С. 5256 - 5259

Опубликована: Сен. 13, 2017

Sulfoxonium ylides act as an efficient carbene precursor in rhodium(III)-catalyzed C-H acylmethlyation of a variety arenes assisted by different chelating groups, and both aryl- alkyl-substituted β-carbonyl sulfoxonium are applicable. The system proceeded under redox-neutral conditions with broad scope, high efficiency, functional group tolerance.

Язык: Английский

---

Rhodium(iii)-catalyzed chemodivergent annulations between N-methoxybenzamides and sulfoxonium ylides via C–H activation

Chemical Communications, Год журнала: 2018, Номер 54(6), С. 670 - 673

Опубликована: Янв. 1, 2018

Rhodium-catalyzed and acid-controlled chemodivergent annulations between N-methoxybenzamides sulfoxonium ylides have been realized.

Язык: Английский

---

Palladium(II)‐Initiated Catellani‐Type Reactions

Angewandte Chemie International Edition, Год журнала: 2018, Номер 58(18), С. 5832 - 5844

Опубликована: Дек. 27, 2018

Abstract The Catellani reaction is known as a powerful strategy for the expeditious synthesis of highly substituted arenes and benzo‐fused rings, which are usually difficult to access through traditional cross‐coupling strategies. It utilizes synergistic interplay palladium norbornene catalysis facilitate sequential ortho C−H functionalization ipso termination aryl halides in single operation. In classical Catellani‐type reactions, mainly used substrates, Pd 0 catalyst required initiate reaction. Nevertheless, recent advances showcase that reactions can also be initiated by II with different starting materials instead via mechanisms under conditions. This emerging concept /norbornene cooperative has significantly advanced thus enabling future developments this field. Minireview, ‐initiated their application bioactive molecules summarized.

Язык: Английский

---

Recent advances in the direct functionalization of quinoxalin-2(1H)-ones

Organic & Biomolecular Chemistry, Год журнала: 2019, Номер 17(24), С. 5863 - 5881

Опубликована: Янв. 1, 2019

The direct C3-functionalization of quinoxalin-2(1H)-ones via C–H bond activation has recently attracted considerable attention, due to their diverse biological activities and chemical properties.

Язык: Английский

---

meta-Selective C–H Borylation of Benzamides and Pyridines by an Iridium–Lewis Acid Bifunctional Catalyst

Journal of the American Chemical Society, Год журнала: 2019, Номер 141(19), С. 7972 - 7979

Опубликована: Апрель 21, 2019

We report herein the iridium-catalyzed meta-selective C–H borylation of benzamides by using a newly designed 2,2′-bipyridine (bpy) ligand bearing an alkylaluminum biphenoxide moiety. also demonstrate C3-selective pyridine with 1,10-phenanthroline (Phen) alkylborane It is proposed that Lewis acid–base interaction between acid moiety and aminocarbonyl group or sp2-hybridized nitrogen atom accelerates reaction controls site-selectivity.

Язык: Английский

---