s-Block Metal Catalysts for the Hydroboration of Unsaturated Bonds

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(9), P. 8261 - 8312

Published: March 7, 2022

The addition of a B–H bond to an unsaturated (polarized or unpolarized) is powerful and atom-economic tool for the synthesis organoboranes. In recent years, s-block organometallics have appeared as alternative catalysts transition-metal complexes, which traditionally catalyze hydroboration bonds. Because rapid development in field bonds catalyzed by alkali (Li, Na, K) alkaline earth (Mg, Ca, Sr, Ba) metals, we provide detailed updated comprehensive review that covers synthesis, reactivity, application metal polarized well carbon–carbon Moreover, describe main reaction mechanisms, providing valuable insight into reactivity catalysts. Finally, compare these complexes with other redox-neutral catalytic systems based on p-block metals including aluminum f-block lanthanides early actinides. this review, aim comprehensive, authoritative, critical assessment state art within highly interesting research area.

Language: Английский

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Carbon Monoxide in Main-Group Chemistry

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(5), P. 2034 - 2050

Published: Jan. 24, 2022

The usage of carbon monoxide (CO) as a C1 feedstock for carbonylation has been an important subject numerous studies over century. chemistry in this field evolved significantly, and several processes (e.g., Fischer-Tropsch, Monsanto, Cativa process) have even industrialized to serve humankind our daily lives. CO is also crucial ligand (carbonyl) organometallic chemistry, transition-metal carbonyl complexes widely used homogeneous catalysts various chemical transformations. Historically, carbonyls considered be dominant these purposes. In recent decades, main-group elements, especially naturally abundant elements the Earth's crust such silicon aluminum, gained much attention, they are eco-friendly low toxicity compared late transition metals. Recent developments revealed reactivity which can mimic that toward small molecules H2, alkenes, alkynes, along with monoxide. This Perspective highlights activation by compounds leads formation or insertion into element center well reductive homologation CO.

Language: Английский

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Recent advances in stable main group element radicals: preparation and characterization

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(14), P. 5930 - 5973

Published: Jan. 1, 2022

Radical species are significant in modern chemistry. Their unique chemical bonding and novel physicochemical properties play roles not only fundamental chemistry, but also materials science. Main group element radicals usually transient due to their high reactivity. Highly stable often stabilized by π-delocalization, sterically demanding ligands, carbenes weakly coordinating anions recent years. This review presents the advances synthesis, characterization, reactivity physical of isolable main radicals.

Language: Английский

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Low oxidation state and hydrido group 2 complexes: synthesis and applications in the activation of gaseous substrates

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(10), P. 5054 - 5082

Published: Jan. 1, 2024

This review summarises advances in the chemistry of low-oxidation state and hydrido group 2 metal complexes, focussing on their use for reductive activation feed-stock gaseous small molecules, subsequent transformation into value added products.

Language: Английский

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Main group metal polymerisation catalysts

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(21), P. 8793 - 8814

Published: Jan. 1, 2022

With sustainability at the forefront of current polymerisation research, typically earth-abundant, inexpensive and low-toxicity main group metals are attractive candidates for catalysis. Main have been exploited in a broad range polymerisations, ranging from classical alkene to synthesis new bio-derived degradable polyesters polycarbonates via ring-opening copolymerisation. This tutorial review highlights efficient catalysts based on Group 1, 2, Zn 13 metals. Key mechanistic pathways catalyst developments discussed, including tailored ligand design, heterometallic cooperativity, bicomponent systems careful selection conditions, all which can be used fine-tune metal Lewis acidity metal-alkyl bond polarity.

Language: Английский

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Magnesium Pincer Complexes and Their Applications in Catalytic Semihydrogenation of Alkynes and Hydrogenation of Alkenes: Evidence for Metal–Ligand Cooperation

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(41), P. 19115 - 19126

Published: Oct. 4, 2022

The development of catalysts for environmentally benign organic transformations is a very active area research. Most the reported so far are based on transition-metal complexes. In recent years, examples catalysis by main-group metal compounds have been reported. Herein, we report series magnesium pincer complexes, which were characterized NMR and X-ray single-crystal diffraction. Reversible activation H2 via aromatization/dearomatization metal–ligand cooperation was studied. Utilizing obtained unprecedented homogeneous catalyzed semihydrogenation alkynes hydrogenation alkenes demonstrated under base-free conditions, affording Z-alkenes alkanes as products, respectively, with excellent yields selectivities. Control experiments DFT studies reveal involvement in reactions. This study not only provides new approach but also offers opportunities other

Language: Английский

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The Green Box: Selenoviologen-Based Tetracationic Cyclophane for Electrochromism, Host–Guest Interactions, and Visible-Light Photocatalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(16), P. 9118 - 9128

Published: April 4, 2023

The novel selenoviologen-based tetracationic cyclophanes (green boxes 3 and 5) with rigid electron-deficient cavities are synthesized via SN2 reactions in two steps. green exhibit good redox properties, narrow energy gaps, strong absorption the visible range (370-470 nm), especially for box 5 containing selenoviologen (SeV2+) units. Meanwhile, femtosecond transient (fs-TA) reveals that have a stabilized dicationic biradical, high efficiency of intramolecular charge transfer (ICT), long-lived separation state due to formation cyclophane structure. Based on excellent photophysical applied electrochromic devices (ECDs) visible-light-driven hydrogen production H2 generation rate (34 μmol/h), turnover number (203), apparent quantum yield (5.33 × 10-2). In addition, host-guest recognitions demonstrated between electron-rich guests (e.g., G1:1-naphthol G2:platinum(II)-tethered naphthalene) MeCN through C-H···π π···π interactions. As one-component system, complexes box⊃G2 successfully visible-light photocatalytic electron (IET) platinum(II) G2 SeV2+ box, which provides simplified system solar conversion.

Language: Английский

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Calcium‐Ligand Cooperation Promoted Activation of N₂O, Amine, and H₂ as well as Catalytic Hydrogenation of Imines, Quinoline, and Alkenes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(21)

Published: March 27, 2024

Abstract Bond activation and catalysis using s‐block metals are of great significance. Herein, a series calcium pincer complexes with deprotonated side arms have been prepared pyridine‐based PNP PNN ligands. The were characterized by NMR X‐ray crystal diffraction. Utilizing the obtained complexes, unprecedented N 2 O metal‐ligand cooperation (MLC) involving dearomatization‐aromatization pyridine ligand was achieved, generating aromatized diazotate as products. Additionally, dearomatized able to activate N−H bond well reversibly H , offering an opportunity for catalytic hydrogenation various unsaturated molecules. DFT calculations applied analyze electronic structures synthesized explore possible reaction mechanisms. This study is important complement area MLC main‐group metal chemistry.

Language: Английский

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Cesium Amide‐Catalyzed Selective Deuteration of Benzylic C‐H Bonds with D₂ and Application for Tritiation of Pharmaceuticals

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(8)

Published: Oct. 27, 2022

Hydrogen isotope exchange (HIE) represents one of the most attractive labeling methods to synthesize deuterium- and tritium-labeled compounds. Catalytic HIE that enable site-selective C-H bond activation with gaseous isotopes D2 T2 are vital importance, in particular for high-specific-activity tritiation pharmaceuticals. As part our interest exploring s-block metals catalytic transformations, we found CsN(SiMe3 )2 be an efficient catalyst selective benzylic bonds gas. The reaction proceeds through a kinetic deprotonative equilibrium establishes pathway between By virtue multiple high activity (isotope enrichment up 99 %), simple cesium amide provided very powerful practically convenient protocol synthesis highly deuterated compounds

Language: Английский

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Free Aluminylenes: An Emerging Class of Compounds

Chemistry - A European Journal, Journal Year: 2022, Volume and Issue: 28(63)

Published: Aug. 9, 2022

Aluminylenes (R-Al) are aluminium analogs of carbenes. In contrast to isolable carbenes, aluminylenes extremely rare species. the past years, pioneered by Schnöckel, Roesky and Power, a few free their complexes have been reported. Such compounds atom in oxidation state +I, which contrasts with classical organoaluminium derivatives that contain element +III state. Aluminylenes, either or coordination sphere Lewis base, capable coordinating transition metals activating inert chemical bonds. Free emerging as potent synthetic platforms for unusual

Language: Английский

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