Palladium/Norbornene Cooperative Catalysis

Chemical Reviews, Год журнала: 2019, Номер 119(12), С. 7478 - 7528

Опубликована: Апрель 25, 2019

Palladium/norbornene cooperative catalysis has emerged as a distinct approach to construct polyfunctionalized arenes from readily available starting materials. This Review provides comprehensive overview of this field, including the early stoichiometric investigations, catalytic reaction developments, well applications in syntheses bioactive compounds and polymers. The section reactions is divided into two parts according initiation mode: Pd(0)-initiated Pd(II)-initiated reactions.

Язык: Английский

---

Palladium-Catalyzed Cross-Coupling Reactions: A Powerful Tool for the Synthesis of Agrochemicals

Journal of Agricultural and Food Chemistry, Год журнала: 2018, Номер 66(34), С. 8914 - 8934

Опубликована: Июль 31, 2018

Pd-catalyzed cross-coupling reactions have become essential tools for the construction of carbon–carbon and carbon–heteroatom bonds. Over last three decades, great efforts been made with chemistry in discovery, development, commercialization innovative new pharmaceuticals agrochemicals (mainly herbicides, fungicides, insecticides). In view growing interest both modern crop protection chemistry, this review gives a comprehensive overview successful applications various methodologies, which implemented as key steps synthesis (on R&D pilot-plant scales) such Heck, Suzuki, Sonogashira, Stille, Negishi reactions, well decarboxylative, carbonylative, α-arylative, carbon–nitrogen bond bond-forming reactions. Some perspectives challenges these catalytic coupling processes discovery are briefly discussed final section. The examples chosen demonstrate that approaches open-up new, low-cost, more efficient industrial routes to existing agrochemicals, methods also capability lead generation pesticides novel modes action sustainable protection.

Язык: Английский

---

Thermal Stability and Explosive Hazard Assessment of Diazo Compounds and Diazo Transfer Reagents

Organic Process Research & Development, Год журнала: 2019, Номер 24(1), С. 67 - 84

Опубликована: Ноя. 28, 2019

Despite their wide use in academia as metal-carbene precursors, diazo compounds are often avoided industry owing to concerns over instability, exothermic decomposition, and potential explosive behavior. The stability of sulfonyl azides other transfer reagents is relatively well understood, but there little reliable data available for compounds. This work first collates sensitivity thermal analysis act an accessible reference resource. Thermogravimetric (TGA), differential scanning calorimetry (DSC), accelerating rate (ARC) the model donor/acceptor compound ethyl (phenyl)diazoacetate presented. We also present a rigorous DSC dataset with 43 compounds, enabling direct comparison energetic materials provide clear academic industrial chemistry communities. Interestingly, range onset temperatures (Tonset) this series which varied between 75 160 °C. variation depends on electronic effect substituents amount charge delocalization. A statistical demonstrated predict differently substituted phenyl diazoacetates. maximum recommended process temperature (TD24) avoid decomposition estimated selected average enthalpy (ΔHD) without functional groups −102 kJ mol–1. Several analyzed using same protocol found have higher stability, general agreement reported values. For azide reagents, ΔHD −201 mol–1 observed. High-quality from ARC experiments shows initiation be 60 °C, compared that 100 °C common reagent p-acetamidobenzenesulfonyl (p-ABSA). Yoshida correlation applied each indication both impact (IS) explosivity. As neat substance, none tested predicted explosive, many (particularly compounds) impact-sensitive. It therefore manipulation, agitation, processing conducted due care impacts, particularly large quantities. full presented inform chemists nature magnitude hazards when reagents. Given rapid heat generation gas evolution, adequate control cautious addition begin reaction strongly conducting reactions

Язык: Английский

---

Blue‐Light‐Induced Carbene‐Transfer Reactions of Diazoalkanes

Angewandte Chemie International Edition, Год журнала: 2018, Номер 58(4), С. 1203 - 1207

Опубликована: Ноя. 27, 2018

Abstract Carbenes are very important reactive intermediates to access a variety of complex molecules and applied widely in organic synthesis drug discovery. Typically, their chemistry is accessed by the use transition metal catalysts. Herein, we describe application low‐energy blue light for photochemical generation carbenes from donor–acceptor diazoalkanes. This catalyst‐free operationally simple approach enables highly efficient cyclopropenation reactions with alkynes rearrangement sulfides under mild reaction conditions, which can be utilized both batch continuous‐flow processes.

Язык: Английский

---

Recent advances in transition-metal-catalyzed carbene insertion to C–H bonds

Chemical Society Reviews, Год журнала: 2022, Номер 51(7), С. 2759 - 2852

Опубликована: Янв. 1, 2022

C-H functionalization has been emerging as a powerful method to establish carbon-carbon and carbon-heteroatom bonds. Many efforts have devoted transition-metal-catalyzed direct transformations of Metal carbenes generated in situ from transition-metal compounds diazo or its equivalents are usually applied the transient reactive intermediates furnish catalytic cycle for new C-C C-X bond formation. Using this strategy unactivated simple alkanes complex molecules can be further functionalized transformed multi-functionalized compounds. In area, carbene insertion bonds paid continuous attention. Diverse catalyst design strategies, synthetic methods, potential applications developed. This critical review will summarize advance dated up July 2021, by categories aliphatic C(sp3)-H, aryl (aromatic) C(sp2)-H, heteroaryl (heteroaromatic) C(sp2)-H bonds, alkenyl alkynyl C(sp)-H, well asymmetric more coverage given recent work. Due rapid development future directions topic also discussed. give authors an overview chemistry with focus on systems

Язык: Английский

---

Pushing Electrons—Which Carbene Ligand for Which Application?

Organometallics, Год журнала: 2018, Номер 37(3), С. 275 - 289

Опубликована: Фев. 12, 2018

This tutorial explores the diversity and characteristics of C-donor ligands. Particular emphasis is put on conceptual design electronic properties for applications in coordination chemistry. More specifically, implications both σ π effects are discussed. Cyclic (alkyl)(amino)carbenes as well methanediides carbones brought perspective to "conventional" N-heterocylic carbenes, mesoionic Fischer Schrock carbene

Язык: Английский

---

Diazo Compounds: Versatile Synthons for the Synthesis of Nitrogen Heterocycles via Transition Metal‐Catalyzed Cascade C–H Activation/Carbene Insertion/Annulation Reactions

Advanced Synthesis & Catalysis, Год журнала: 2018, Номер 361(5), С. 919 - 944

Опубликована: Ноя. 27, 2018

Abstract This review covers some unique diazo compounds, the coupling partners to access various versatile functionalized nitrogen heterocycles, such as indoles, indolines, isoquinolines, isoquinolones, and so on. Different transition metals (such Rh, Pd, Ru, Ir, Cu, Co) are involved in these transformations, which involve consecutive processes: metal‐catalyzed cascade C–H activation/carbene insertion/intramolecular annulation. magnified image

Язык: Английский

---

Transition-Metal-Catalyzed Cross-Coupling with Ketones or Aldehydes via N-Tosylhydrazones

Journal of the American Chemical Society, Год журнала: 2020, Номер 142(24), С. 10592 - 10605

Опубликована: Май 22, 2020

Ketones and aldehydes play central roles in organic synthesis. There are numerous broadly used reactions that related to the carbonyl reactivity, such as Grignard reactions, Wittig aldol so on. In addition, formation of enol triflates is a classic protocol enables ketones be applied transition-metal-catalyzed cross-coupling which case considered precursors alkenyl electrophiles C-C bond-forming transformations. past decade, new type ketone- or aldehyde-based transformations has emerged. this first converted their corresponding N-tosylhydrazones, employed reaction partners various carbene-based reactions. The N-tosylhydrazone-based carbene couplings significantly enhance potential modern This Perspective aims give an overview coupling with N-tosylhydrazones from viewpoint exploring potentials

Язык: Английский

---

Chiral proton-transfer shuttle catalysts for carbene insertion reactions

Organic & Biomolecular Chemistry, Год журнала: 2018, Номер 16(17), С. 3087 - 3094

Опубликована: Янв. 1, 2018

The development of chiral proton-transfer shuttles provides a totally new enantiocontrol strategy for transition metal-catalyzed asymmetric carbene insertion reactions.

Язык: Английский

---

Lightening Diazo Compounds?

ACS Sustainable Chemistry & Engineering, Год журнала: 2021, Номер 9(27), С. 8895 - 8918

Опубликована: Июнь 25, 2021

The development of new sustainable reactions and protocols is essential to fulfill the growing demands every branch organic chemistry for greener synthetic methodologies. In this context, use visible light as only source energy highly appealing. Since diazo compounds are valuable reagents in synthesis, their transformations realized a manner interest. High reactivity easy availability make them suitable solar-driven transformations. Indeed, photochemical have recently proven alternative transition metal catalysis. perspective, we highlight applications these under irradiation, particularly focusing on recent advancements. These include generation carbenes radicals which involve many relevant reactions, [2+1]-cycloadditions, X–H C–H insertions, Wolff rearrangement, more. Mechanistic aspects processes briefly addressed give readers deeper understanding rules underlying photoreactivity compounds. We conclude by emphasizing significant advancements discussing challenges future developments photochemistry reagents.

Язык: Английский

---