Methodologies and Strategies for Selective Borylation of C–Het and C–C Bonds

Chemical Reviews, Год журнала: 2020, Номер 120(15), С. 7348 - 7398

Опубликована: Июнь 29, 2020

Organoborons have emerged as versatile building blocks in organic synthesis to achieve molecular diversity and carboxylic acid bioisosteres with broad applicability drug discovery. Traditionally, these compounds are prepared by the substitution of Grignard/lithium reagents electrophilic boron species Brown hydroboration. Recent developments provided new routes for efficient preparation organoborons applying reactions using chemical feedstocks leaving groups. As compared previous methods that used halides (I, Br, Cl), direct borylation less reactive C–Het C–C bonds has become highly important get efficiency functional-group compatibility. This Review aims provide a comprehensive overview this topic, including (1) C–F bond borylation, (2) C–O (3) C–S (4) C–N (5) borylation. Considerable attention is given strategies mechanisms involved. We expect will inspire chemists discover more transformations expand field.

Язык: Английский

---

Sequential C–F bond functionalizations of trifluoroacetamides and acetates via spin-center shifts

Science, Год журнала: 2021, Номер 371(6535), С. 1232 - 1240

Опубликована: Март 5, 2021

Defluorinative functionalization of readily accessible trifluoromethyl groups constitutes an economical route to partially fluorinated molecules. However, the controllable replacement one or two fluorine atoms while maintaining high chemoselectivity remains a formidable challenge. Here we describe general strategy for sequential carbon-fluorine (C-F) bond functionalizations trifluoroacetamides and trifluoroacetates. The reaction begins with activation carbonyl oxygen atom by 4-dimethylaminopyridine-boryl radical, followed spin-center shift trigger C-F scission. A chemoselectivity-controllable two-stage process enables generation difluoro- monofluoroalkyl radicals, which are selectively functionalized different radical traps afford diverse products. mechanism origin were established experimental computational approaches.

Язык: Английский

---

Nickel-catalyzed allylic defluorinative alkylation of trifluoromethyl alkenes with reductive decarboxylation of redox-active esters

Chemical Science, Год журнала: 2018, Номер 10(3), С. 809 - 814

Опубликована: Ноя. 7, 2018

Synthesis of functionalized gem-difluoroalkenes was achieved through nickel-catalyzed allylic defluorinative alkylation trifluoromethyl alkenes with reductive decarboxylation redox-active esters.

Язык: Английский

---

Visible‐Light‐Induced Selective Defluoroborylation of Polyfluoroarenes, gem‐Difluoroalkenes, and Trifluoromethylalkenes

Angewandte Chemie International Edition, Год журнала: 2019, Номер 59(10), С. 4009 - 4016

Опубликована: Дек. 18, 2019

Fluorinated organoboranes serve as versatile synthetic precursors for the preparation of value-added fluorinated organic compounds. Recent progress has been mainly focused on transition-metal catalyzed defluoroborylation. Herein, we report a photocatalytic defluoroborylation platform through direct B-H activation N-heterocyclic carbene boranes, synergistic merger photoredox catalyst and hydrogen atom transfer catalyst. This atom-economic operationally simple protocol enabled an extremely broad scope multifluorinated substrates including polyfluoroarenes, gem-difluoroalkenes, trifluoromethylalkenes in highly selective fashion. Intriguingly, can be free, regioselectivity obtained is complementary to reported transition-metal-catalysis many cases.

Язык: Английский

---

Visible-Light-Driven Catalytic Reductive Carboxylation with CO₂

ACS Catalysis, Год журнала: 2020, Номер 10(19), С. 10871 - 10885

Опубликована: Авг. 28, 2020

Carbon dioxide (CO2) is an important C1 source for the generation of carboxylic acids and derivatives. Stoichiometric catalytic carboxylation nucleophiles, including organometallic reagents, with CO2 has been widely investigated. Since many kinds reagents are prepared from electrophiles, transition-metal-catalyzed direct diverse electrophiles attracted much attention high step economy user-friendly protocols. Although significant progress achieved, use stoichiometric metallic or pyrophoric reductants common. The renaissance photochemistry seen numerous efforts devoted to light-driven CO2, which become one most active directions in this field. In Perspective, we summarize recent advances visible-light-driven reductive substrates, such as unsaturated hydrocarbons, organic (pseudo)halides, imines, presence mild electron donors, amines, Hantzsch esters, formates. We highlight mechanisms reactions, can proceed absence a photoredox catalyst dual visible light photoredox/transition metal system. also discuss future field offer some insight into challenges that remain.

Язык: Английский

---

Recent advances in the synthesis and applications of α-(trifluoromethyl)styrenes in organic synthesis

Chemical Communications, Год журнала: 2019, Номер 55(90), С. 13486 - 13505

Опубликована: Янв. 1, 2019

α-Trifluoromethylstyrene derivatives are versatile synthetic intermediates for the preparation of more complex fluorinated compounds. Much attention has been paid to these compounds by organic chemistry community, because they have successfully utilized in C-F bond activation a CF3 group, mainly including anionic SN2'-type substitution, cationic SN1'-type ipso-substitution and defluorinative functionalization with transition metals or photoredox catalysts. In addition, metal-catalyzed cycloaddition reactions α-trifluoromethylstyrenes developed construction cycloalkanes cycloalkenes containing fluoro trifluoromethyl groups. this review, we systematically summarized synthesis their applications chemistry, mechanisms were also discussed.

Язык: Английский

---

Recent advance in the C–F bond functionalization of trifluoromethyl-containing compounds

Organic Chemistry Frontiers, Год журнала: 2021, Номер 8(14), С. 3915 - 3942

Опубликована: Янв. 1, 2021

The C–F bond is the strongest single in organic compounds.

Язык: Английский

---

Recent Advances in Alkenyl sp² C–H and C–F Bond Functionalizations: Scope, Mechanism, and Applications

Chemical Reviews, Год журнала: 2022, Номер 122(24), С. 17479 - 17646

Опубликована: Окт. 14, 2022

Alkenes and their derivatives are featured widely in a variety of natural products, pharmaceuticals, advanced materials. Significant efforts have been made toward the development new practical methods to access this important class compounds by selectively activating alkenyl C(sp2)–H bonds recent years. In comprehensive review, we describe state-of-the-art strategies for direct functionalization sp2 C–H C–F until June 2022. Moreover, metal-free, photoredox, electrochemical also covered. For clarity, review has divided into two parts; first part focuses on currently available using different alkene as starting materials, second describes bond easily accessible gem-difluoroalkenes material. This includes scope, limitations, mechanistic studies, stereoselective control (using directing groups well metal-migration strategies), applications complex molecule synthesis where appropriate. Overall, aims document considerable advancements, current status, emerging work critically summarizing contributions researchers working fascinating area is expected stimulate novel, innovative, broadly applicable functionalizations coming

Язык: Английский

---

Visible-Light-Induced Palladium-Catalyzed Selective Defluoroarylation of Trifluoromethylarenes with Arylboronic Acids

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(34), С. 13971 - 13979

Опубликована: Авг. 19, 2021

Selective functionalization of inactive C(sp3)-F bonds to prepare medicinally interesting aryldifluoromethylated compounds remains challenging. One promising route is the transition-metal-catalyzed cross-coupling through oxidative addition bond in trifluoromethylarenes (ArCF3), which are ideal precursors for this process due their ready availability and low cost. Here, we report an unprecedented excited-state palladium catalysis strategy selective defluoroarylation with arylboronic acids. This visible-light-induced palladium-catalyzed proceeds under mild reaction conditions allows transformation a variety acids ArCF3. Preliminary mechanistic studies reveal that ArCF3 palladium(0) via single electron transfer pathway responsible activation.

Язык: Английский

---

Visible-light photoredox-catalyzed selective carboxylation of C(sp3)−F bonds with CO2

Chem, Год журнала: 2021, Номер 7(11), С. 3099 - 3113

Опубликована: Авг. 27, 2021

Язык: Английский

---