Exploiting Heavier Organochalcogen Compounds in Donor–Acceptor Cyclopropane Chemistry

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(6), P. 1528 - 1541

Published: March 4, 2021

ConspectusDonor–acceptor (D–A) cyclopropanes have gained increased momentum over the past two decades. The use of these highly strained three-membered entities paved way to innovative and original transformations yielding complex cyclic acyclic architectures that otherwise might be difficult address. Since fundamentals were laid by Wenkert Reissig in late 1970s, field has flourished impressively including asymmetric as well elegant synthetic applications construction natural occurring products. In this Account, we aim highlight especially our efforts context an efficient access sulfur- selenium-containing compounds, either or open-chain nature, exploiting D–A cyclopropane chemistry. Light will shed on three fundamental transformations: ring-opening reactions, cycloadditions, rearrangements.Our endeavors started back 2011 guided quantum chemical studies obtain 3,3′-linked bisthiophenes along with unprecedented rearrangement delivering cagelike scaffolds. Inspired surprising results, further deepened new sulfur–carbon selenium–carbon bonds within first instance, capitalized great versatility organosulfur organoselenium compounds regarding their amphiphilic character act nucleophilic electrophilic species. By such approach, ring-openings via a attack sulfenyl selenyl halides furnished 1,3-bishalochalcogenated A similar protocol led us desymmetrization reaction meso-cyclopropyl carbaldehydes employing novel chiral imidazolidinone organocatalysts. contrast, sulfur was supplied N-(arylthio)succinimide substrates thiolated γ-amino acid derivatives selenium equivalents.Combining reactive thiocarbonyl vicinal donor–acceptor substituted opened vistas atom-economic cycloaddition reactions build up sulfur-containing heterocycles various sizes. systematic study made group 2017 leading decorated thiolanes, whereas intramolecular approach thia-[n.2.1]bicyclic ring systems. Our investigations then successfully extended synthesis tetrahydroselenophenes using capricious selenoketones. Recently, able yield unsaturated analogues, selenophenes, (3 + 2)-cycloaddition ammonium selenocyanates followed oxidation. formal insertion thioketenes realized 3-thioxocyclobutanones surrogates for disubstituted 2-substituted tetrahydrothiophenes bearing semicyclic double bond 2) spiroannulation/(2 cycloreversion sequence. Even formation seven-membered S-heterocycles (4 3)-cycloaddition processes. 2016, demonstrated benzo-fused dithiepines from situ generated ortho-bisthioquinones, utilization thia-Michael systems hetero-4π-component delivered tetrahydrothiepine containing just one atom embedded system.

Language: Английский

---

Electrochemical Ring-Opening Dicarboxylation of Strained Carbon–Carbon Single Bonds with CO₂: Facile Synthesis of Diacids and Derivatization into Polyesters

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(5), P. 2062 - 2068

Published: Jan. 27, 2022

Diacids are important monomers in the polymer industry to construct valuable materials. Dicarboxylation of unsaturated bonds, such as alkenes and alkynes, with CO2 has been demonstrated a promising synthetic method. However, dicarboxylation C─C single bonds rarely investigated. Herein we report novel electrochemical ring-opening strained rings CO2. Structurally diverse glutaric acid adipic derivatives were synthesized from substituted cyclopropanes cyclobutanes moderate high yields. In contrast oxidative ring openings, this is also first realization an electroreductive reaction rings, including commercialized ones. Control experiments suggested that radical anions carbanions might be key intermediates reaction. Moreover, process features step atom economy, mild conditions (1 atm, room temperature), good chemoselectivity functional group tolerance, low electrolyte concentration, easy derivatization products. Furthermore, conducted polymerization corresponding diesters diols obtain potential UV-shielding material self-healing function fluorine-containing polyester, whose performance tests showed applications.

Language: Английский

---

Cooperative NHC/Photoredox Catalyzed Ring‐Opening of Aryl Cyclopropanes to 1‐Aroyloxylated‐3‐Acylated Alkanes

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(48), P. 25252 - 25257

Published: Sept. 28, 2021

Cyclopropanes are an important class of building blocks in organic synthesis. Herein, a ring-opening/arylcarboxylation/acylation cascade reaction for the 1,3-difunctionalization aryl cyclopropanes enabled by cooperative NHC and organophotoredox catalysis is reported. The works on monosubstituted that contrast to heavily investigated donor-acceptor more challenging be difunctionalized. key step radical/radical cross coupling benzylic radical generated photoredox cycle with ketyl from cycle. transformation features metal-free conditions tolerates diverse range functionalities.

Language: Английский

---

Photocatalyzed [2σ + 2σ] and [2σ + 2π] Cycloadditions for the Synthesis of Bicyclo[3.1.1]heptanes and 5- or 6-Membered Carbocycles

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(46), P. 25411 - 25421

Published: Nov. 7, 2023

We report the use of photocatalysis for homolytic ring-opening carbonyl cyclopropanes. In contrast to previous studies, our approach does not require a metal cocatalyst or strong reductant. The cyclopropanes can be employed both [2σ + 2σ] and 2π] annulation with either alkenes/alkynes bicyclo[1.1.0]butanes, yielding cyclopent-anes/-enes bicyclo[3.1.1]heptanes (BCHs), respectively. BCHs are promising bioisosteres 1,2,4,5 tetra-substituted aromatic rings. Mechanistic including density functional theory computation trapping experiment DMPO, support 1,3-biradical generated from cyclopropane as key intermediate these transformations.

Language: Английский

---

High-order dipolar annulations with metal-containing reactive dipoles

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(10), P. 4146 - 4174

Published: Jan. 1, 2022

The advances on metal-catalysed high-order dipolar annulations were comprehensively summarized in this review. To further exploit the potential of unique annulation strategy, a research outlook was also proposed.

Language: Английский

---

Intermolecular Formal Cycloaddition of Indoles with Bicyclo[1.1.0]butanes by Lewis Acid Catalysis

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(48)

Published: Aug. 16, 2023

Abstract Herein, we develop a new approach to directly access architecturally complex polycyclic indolines from readily available indoles and bicyclo[1.1.0]butanes (BCBs) through formal cycloaddition promoted by commercially Lewis acids. The reaction proceeded stepwise pathway involving nucleophilic addition of BCBs followed an intramolecular Mannich form rigid indoline‐fused structures, which resemble indole alkaloids. This tolerated wide range BCBs, thereby allowing the one‐step construction various indoline polycycles containing up four contiguous quaternary carbon centers.

Language: Английский

---

Organoelectrocatalysis Enables Direct Cyclopropanation of Methylene Compounds

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(5), P. 2343 - 2350

Published: Feb. 1, 2022

Cyclopropane is a prevalent structural unit in natural products and bioactive compounds. While the transition metal-catalyzed alkene cyclopropanation of functionalized compounds such as α-diazocarbonyl derivatives has been well established provides straightforward access to cyclopropanes, directly from more stable simpler methylene remained an unsolved challenge despite highly desirable benefits minimal prefunctionalization increased operational safety. Herein we report electrocatalytic strategy for active compounds, employing organic catalyst. The method shows broad substrate scope excellent scalability, requires no metal catalyst or external chemical oxidant, convenient several types cyclopropane-fused heterocyclic carbocyclic Mechanistic investigations suggest that reactions proceed through radical-polar crossover process form two new carbon-carbon bonds nascent cyclopropane ring.

Language: Английский

---

Palladium-Catalyzed Siloxycyclopropanation of Alkenes Using Acylsilanes

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(3), P. 1099 - 1105

Published: Jan. 12, 2022

Currently, catalytically transferable carbenes are limited to electron-deficient and neutral derivatives, electron-rich bearing an alkoxy group (i.e., Fischer-type carbenes) cannot be used in catalytic cyclopropanation because of the lack appropriate carbene precursors. We report herein that acylsilanes can serve as a source under palladium catalysis, enabling range alkenes. This reactivity profile is sharp contrast metal-free siloxycarbenes, which unreactive toward normal The resulting siloxycyclopropanes valuable homoenolate equivalents, allowing rapid access elaborate β-functionalized ketones.

Language: Английский

---

Diastereoselective Transfer of Tri(di)fluoroacetylsilanes‐Derived Carbenes to Alkenes

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(25)

Published: April 13, 2022

Stereoselective cyclopropanation reaction of alkenes is usually achieved by metal complexes via singlet-metal-carbene intermediates. However, previous transition-metal-catalyzed with acylsilanes afforded low diastereoselectivity. Herein, we report the first visible-light-induced transition-metal-free terminal trifluoroacetylsilanes and difluoroacetylsilanes. Both aromatic aliphatic as well electron-deficient are suitable substrates for highly cis-selective [2+1] cyclization reaction. A combination experimental computational studies identified triplet carbenes being key intermediates in this transformation. The gram scale late-stage functionalization demonstrated synthetic potential strategy.

Language: Английский

---

Visible Light-Induced Reactions of Diazo Compounds and Their Precursors

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(11), P. 7214 - 7261

Published: May 16, 2024

In recent years, visible light-induced reactions of diazo compounds have attracted increasing attention in organic synthesis, leading to improvement existing reactions, as well the discovery unprecedented transformations. Thus, photochemical or photocatalytic generation both carbenes and radicals provide milder tools toward these key intermediates for many valuable However, vast majority transformations represent new reactivity modes compounds, which are achieved by decomposition photoredox catalysis. particular, use a redox-active photocatalysts opens avenue plethora radical reactions. The application methods led inaccessible classical associated with metal carbenes. most cases, act sources but can also serve acceptors. Importantly, described processes operate under mild, practical conditions. This Review describes this subfield compound chemistry, particularly focusing on advancements.

Language: Английский

---