Recent Advances in Ni‐Catalyzed 1,1‐Difunctionalization of Unactivated Olefins

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 366(4), P. 593 - 602

Published: Dec. 7, 2023

Abstract Unactivated olefins rank amongst the most important feedstocks in organic synthesis. Their availability makes them particularly useful synthons for subsequent functionalization, a catalytic manner. Driven by popularity ascribed nickel catalysis as new tool to rapidly forge molecular architectures via one‐or two‐electron manifolds, recent years have witnessed significant advances Ni‐catalyzed olefin difunctionalization. While 1,2‐difunctionalization or remote functionalization “chain‐walk” become mature disciplines repurposing potential of building blocks, it was only recently that extensions this chemistry 1,1‐difunctionalization been possible. This review summarizes 1,1‐difunctionalization, holding considerable promise powerful strategy our ever‐growing synthetic repertoire.

Language: Английский

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Bis(diiminate)-Supported Bimetallic Complexes: Tri-Coordinated Zinc for Nitrile and Carbodiimide Hydroboration

ACS Omega, Journal Year: 2025, Volume and Issue: 10(2), P. 2033 - 2043

Published: Jan. 10, 2025

We report the synthesis and characterization of bis(diiminate)-supported tricoordinated zinc complexes (1–4) demonstrate catalytic activity one representative compound in hydroboration nitriles carbodiimides using pinacolborane (HBpin). Experimental theoretical studies were performed to elucidate reaction mechanism. Our findings indicate that initiates with formation a hydride intermediate, followed by subsequent attack carbodiimides. This leads four-membered metallacycle before release diborylated amine. work provides access new types highlights its effectiveness carbodiimides, offering milder alternative existing reduction methods.

Language: Английский

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Azolium-2-dithiocarboxylates as redox active ligands in nickel chemistry

Chemical Science, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

The coordination chemistry of carbene-CS2 adducts selected NHCs and cAACs their redox active nature in nickel complexes is reported. These azolium-2-dithiocarboxylate ligands can be considered as 1,1-isomeric dithiolene analogues bearing a 2π electron reservoir. Depending on the co-ligands attached to nickel, square planar mono- or bis-(carbene-CS2) types [Ni(IiPr)2(carbene-CS2)] (2a-g) (carbene = cAACMe, IDipp, IMes, BIMe, BIiPr, IiPr, IiPrMe) [Ni(carbene-CS2)2] (3a-c) IMes) are accessible by alkene substitution using [Ni(IiPr)2(ƞ2-C2H4)] [Ni(COD)2] starting material (cAACMe 1-(2,6-di-iso-propylphenyl)-3,3,5,5-tetramethylpyrrolidin-2-ylidene, IR 1,3-diorganylimidazolin-2-ylidene, IRMe 1,3-diorganyl-4,5-dimethylimidazolin-2-ylidene, BIR 1,3-diorganylbenzimidazolin-2-ylidene). In 2a-g 3a-c, all coordinated κ2-S,S' fashion nickel(ii) ligated either formally one reduced two states. 3a-c reveal intense NIR absorptions, which shift upon metallic reduction nickelate salts type [Cat]+[Ni(carbene-CS2)2]˙- (4a-bcat). these nickelates, an additional shared across ligand-centered SOMO π-symmetry delocalized over both results moieties with formal -1.5 charge per ligand, further demonstrating flexible ligands.

Language: Английский

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The π-Annulated Carbene 1,3-Di-iso-propylbenzimidazolin-2-ylidene (BIiPr) and Its Application in Nickel(0) Chemistry

Organometallics, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 25, 2025

The stereoelectronic parameters of the π-annulated carbene 1,3-di-iso-propylbenzimidazolin-2-ylidene (BIiPr) were evaluated in this study. N-iso-propyl substituents and additional π-backbone BIiPr lead to a moderate steric bulk, which lies between that backbone unsubstituted IiPr its methylated congener IiPrMe (IR = 1,3-diorganylimidazolin-2-ylidene; IRMe 1,3-diorganyl-4,5-dimethylimidazolin-2-ylidene). While net electron donation properties are slightly lower than those IiPrMe, π-acidity is significantly higher imidazole-based NHCs cAACs. These unique led distinctly different reactivities with Ni(0) reagents comparison IiPrMe. reaction [Ni(COD)2] afforded homoleptic three-coordinated [Ni(BIiPr)3] (1) olefin complex [Ni2(BIiPr)4(μ2-(η2:η2)-COD)] (2) only as side product. [Ni(CO)4] yielded [Ni(BIiPr)2(CO)2] (3), was employed starting material for facile synthesis uncapped, NHC-ligated nickel Chini-cluster analog [Ni3(BIiPr)3(μ2-CO)3] (4). This cluster synthesized from 3 [Ni(COD)2]. results demonstrate reveal influence small variations substitutional pattern on stabilities transition metal complexes.

Language: Английский

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NHC-ligated nickel(ii) cyanoborate complexes and salts

Dalton Transactions, Journal Year: 2024, Volume and Issue: 53(12), P. 5391 - 5400

Published: Jan. 1, 2024

The synthesis and characterization of NHC-ligated nickel( ii ) cyanoborate (CB) complexes salts is reported. diverse character CBs as weakly to medium coordinating anions demonstrated, which dependents on the nature CB NHC.

Language: Английский

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Chemoselective C(sp)–H borylation of terminal alkynes catalyzed by a bis(N-heterocyclicsilylene) manganese complex

Inorganic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(20), P. 6067 - 6076

Published: Jan. 1, 2023

The manganese( ii ) complex [Mn(SiNSi)Cl 2 ] (SiNSi = 2,6-[EtNSi(N t Bu) CPh] C 5 H 3 N) is an efficient catalyst for the chemoselective C(sp)–H borylation of terminal alkynes.

Language: Английский

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Regioselective Hydroboration of Unsymmetrical Internal Alkynes Catalyzed by a Cobalt Pincer-NHC Complex

Organic Letters, Journal Year: 2024, Volume and Issue: 26(27), P. 5862 - 5867

Published: June 27, 2024

Highly regioselective hydroboration of unsymmetrical internal alkynes remains a significant challenge for synthesizing valuable alkenylboronate esters. Herein, we describe an easily synthesizable pincer NHC-based Co complex as catalyst the cis-α selective unactivated and cis-β activated with pinacolborane. The reaction showcases high chemo-, regio-, stereoselectivity, displays efficiency very low loading under base-free conditions. scope was demonstrated by having variety functional groups. mechanistic studies suggest feasible Co-boryl intermediate to explain unusual regioselectivity.

Language: Английский

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Nickel-Catalyzed Secondary Benzylic C–O Bond Borylation

Organic Letters, Journal Year: 2024, Volume and Issue: 26(37), P. 7932 - 7937

Published: Sept. 9, 2024

A remote steric hindrance ligand (

Language: Английский

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Catalyst-free diboration and silaboration of alkenes and alkynes using bis(9-heterofluorenyl)s

Chemical Science, Journal Year: 2023, Volume and Issue: 14(17), P. 4589 - 4596

Published: Jan. 1, 2023

9-Borafluorene-based diboranes and silylboranes spontaneously add to CC or CC bonds. Despite their different charge bond polarization, key orbital interactions of substrate activation are identical for both valence isoelectronic derivatives.

Language: Английский

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On the Reactivity of a NHC Nickel Bis‐Boryl Complex: Reductive Elimination and Formation of Mono‐Boryl Complexes

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(62)

Published: Aug. 8, 2023

The synthesis of the first terminal mono-boryl complexes nickel, which are not stabilized by a pincer ligand, is reported. reaction nickel bis-boryl complex cis-[Ni(i Pr2 ImMe )2 (Bcat)2 ] 1 (cat=1,2-O2 C6 H4 ) with small donor ligand PMe3 led to complete exchange at reductive elimination B2 cat2 and formation bis-NHC adduct [B2 ⋅ (i 3 [Ni(PMe3 )4 2 as metal-containing species. Electrophilic attack MeI on or dismutation trans-[Ni(i Br2 loss only one boryl afforded (Bcat)Br] 4 (Bcat)I] b.

Language: Английский

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