First-Row d-Block Element-Catalyzed Carbon–Boron Bond Formation and Related Processes

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(21), P. 13238 - 13341

Published: Oct. 7, 2021

Organoboron reagents represent a unique class of compounds because their utility in modern synthetic organic chemistry, often affording unprecedented reactivity. The transformation the carbon–boron bond into carbon–X (X = C, N, and O) stereocontrolled fashion has become invaluable medicinal agrochemistry, natural products chemistry as well materials science. Over past decade, first-row d-block transition metals have increasingly widely used catalysts for formation bond, traditionally catalyzed by expensive precious metals. This recent focus on alternative enabled growth fundamental methods organoboron chemistry. review surveys current state-of-the-art use element-based bonds.

Language: Английский

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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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Hidden Boron Catalysis: Nucleophile-Promoted Decomposition of HBpin

Organic Letters, Journal Year: 2020, Volume and Issue: 22(11), P. 4107 - 4112

Published: May 7, 2020

Simple nucleophiles with structural similarities to known hydroboration catalysts can readily mediate the formation of BH3 and borohydride species from pinacolborane (HBpin). Alkyne alkene reactions were successfully mediated by through generation, BH3-catalyzed found dominate catalysis. NMR spectroscopy kinetic analyses showed that NaOtBu, Na[N(SiMe3)2], nBu2Mg, nBuLi only promoted not "true" catalysts.

Language: Английский

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The Hidden Role of Boranes and Borohydrides in Hydroboration Catalysis

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(22), P. 13479 - 13486

Published: Nov. 4, 2020

The continued development of hydroboration catalysts typifies the importance this transformation as a testbed for catalytic activity and fundamental reaction organic synthesis. Catalytic studies routinely investigated decomposition HBcat but in case HBpin, is not commonly considered because its perceived stability. Organoboranes catalyze alkenes alkynes; these species can be formed from facile 1,3,2-dioxaborolanes (e.g., HBpin) by nucleophiles Lewis acids. Similarly, nucleophilic to borohydride reduction carbonyl derivatives. These motifs are abundant catalysis; therefore, potential hidden boron catalysis high must controlled for. This Perspective discusses current methods probing 1,3,2-dioxaborolane decomposition, highlights need consider future catalysis, proposes set protocols identification catalysis.

Language: Английский

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Hydrosilylation and hydroboration in a sustainable manner: from Earth-abundant catalysts to catalyst-free solutions

Green Chemistry, Journal Year: 2020, Volume and Issue: 22(16), P. 5210 - 5224

Published: Jan. 1, 2020

Hydroelementation enables a facile reduction or functionalization of several unsaturated systems, and thus activation such bonds like B–H Si–H is powerful synthetic tool.

Language: Английский

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Overview of Regioselective and Stereoselective Catalytic Hydroboration of Alkynes

Advanced Synthesis & Catalysis, Journal Year: 2021, Volume and Issue: 363(21), P. 4818 - 4840

Published: Sept. 16, 2021

Abstract Hydroboration of alkynes is special interest to researchers since it the most straightforward process for synthesis highly important vinylborane synthetic intermediate compounds. It significant in terms both regioselectivity and stereoselectivity, several positional isomers are formed during hydroboration. Given importance this class compounds, an extensive study has been carried out regarding catalytic condition development detailed mechanistic studies selectively obtaining a single isomer. This review comprehensively summarizes regioselective stereoselective hydroboration alkynes. aimed at giving readers accurate knowledge systems available certain We anticipate that inclusive will encourage explore more new types achieve remarkable magnified image

Language: Английский

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Aluminum-Catalyzed Selective Hydroboration of Nitriles and Alkynes: A Multifunctional Catalyst

The Journal of Organic Chemistry, Journal Year: 2020, Volume and Issue: 85(7), P. 4999 - 5009

Published: March 11, 2020

The reaction of LH [L = {(ArNH)(ArN)-C=N-C=(NAr)(NHAr)}; Ar =2,6-Et2-C6H3] with a commercially available alane amine adduct (H3Al·NMe2Et) in toluene resulted the formation conjugated bis-guanidinate (CBG)-supported aluminum dihydride complex, i.e., LAlH2 (1), good yield. new complex has been thoroughly characterized by multinuclear magnetic resonance, IR, mass, and elemental analyses, including single-crystal structural studies. Further, we have demonstrated aluminum-catalyzed hydroboration variety nitriles alkynes. Moreover, is expanded to more challenging substrates such as alkene, pyridine, imine, carbodiimide, isocyanides. More importantly, shown that catalyzed both intra- intermolecular chemoselective alkynes over other reducible functionalities for first time.

Language: Английский

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Metal‐Terpyridine Complexes in Catalytic Application – A Spotlight on the Last Decade

ChemCatChem, Journal Year: 2020, Volume and Issue: 12(11), P. 2890 - 2941

Published: Jan. 30, 2020

Abstract 2,2′:6′,2′′‐Terpyridine (tpy) and its derivatives represent highly versatile ligands for the complexation of transition metal ions. Today, such complexes are employed in a diverse fashion – including inter alia materials science, opto‐electronics, pharmacy or catalysis. Concerning latter one, vast development has led to new improved applications both “conventional” organic chemistry ( i. e ., catalysis functional‐group interconversions, CH‐activation cross‐coupling reactions) as well energy‐related e. g CO 2 reduction, artificial photosynthesis, dye degradation). In this respect, not only homogeneous catalysts molecular complexes) but also heterogeneous recyclable ones have moved focus interest. These structures include 1D metallopolymers, metal‐organic frameworks (MOFs), organic‐inorganic hybrids bio‐inspired catalysts. We gave first overview on topic already 2011; here, methods implementations established within last decade relevant contributions from earlier works presented discussed.

Language: Английский

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Polynuclear lanthanide–diketonato clusters for the catalytic hydroboration of carboxamides and esters

Nature Catalysis, Journal Year: 2020, Volume and Issue: 3(2), P. 154 - 162

Published: Jan. 6, 2020

Language: Английский

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Cyclic (Alkyl)(amino)carbene Ligand-Promoted Nitro Deoxygenative Hydroboration with Chromium Catalysis: Scope, Mechanism, and Applications

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(3), P. 1618 - 1629

Published: Jan. 7, 2021

Transition metal catalysis that utilizes N-heterocyclic carbenes as noninnocent ligands in promoting transformations has not been well studied. We report here a cyclic (alkyl)(amino)carbene (CAAC) ligand-promoted nitro deoxygenative hydroboration with cost-effective chromium catalysis. Using 1 mol % of CAAC–Cr precatalyst, the addition HBpin to scaffolds leads deoxygenation, allowing for retention various reducible functionalities and compatibility sensitive groups toward hydroboration, thereby providing mild, chemoselective, facile strategy form anilines, heteroaryl aliphatic amine derivatives, broad scope particularly high turnover numbers (up 1.8 × 106). Mechanistic studies, based on theoretical calculations, indicate CAAC ligand plays an important role polarity reversal hydride HBpin; it serves H-shuttle facilitate hydroboration. The preparation several commercially available pharmaceuticals by means this highlights its potential application medicinal chemistry.

Language: Английский

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