Ligand‐Dictated Regiodivergent Allylic Functionalizations via Palladium‐Catalyzed Remote Substitution

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(28)

Опубликована: Март 15, 2023

Different from classical allylic substitutions that require a vicinal leaving group, an olefin bearing remote group is scarcely viewed as potential allylation substrate. Herein, we describe feasible protocols to achieve regiodivergent C-H functionalizations via palladium-catalyzed substitution, which provides novel strategy for the seldomly studied migratory Tsuji-Trost reaction. Dictated by suitable ligand, process involved 4,3-hydrofunctionalization of generated conjugated diene intermediate metal walking observed in generally >20 : 1 regioselectivity. Unexpectedly, related 1,4-hydrofunctionalization pathway found be major route with newly synthesized electron-rich bisphosphine challenges conventional viewpoint on regioselectivity hydrofunctionalizations linear internal dienes η3 -substitution. A series deuterium experiments and kinetic studies provide preliminary insight into catalytic cycle.

Язык: Английский

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Cobalt-Catalyzed Enantioselective Hydroboration of α-Substituted Acrylates

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(10), С. 6604 - 6617

Опубликована: Март 3, 2024

Even though metal-catalyzed enantioselective hydroborations of alkenes have attracted enormous attention, few preparatively useful reactions α-alkyl acrylic acid derivatives are known, and most use rhodium catalysts. No examples asymmetric hydroboration the corresponding α-arylacrylic esters known. In our continuing efforts to search for new applications earth-abundant cobalt catalysts broadly applicable organic transformations, we identified 2-(2-diarylphosphinophenyl)oxazoline ligands mild reaction conditions efficient highly regio- α-alkyl- α-aryl- acrylates, giving β-borylated propionates. Since C-B bonds in these compounds can be readily replaced by C-O, C-N, C-C bonds, intermediates could serve as valuable chiral synthons, some from feedstock carbon sources, synthesis propionate-bearing motifs including polyketides related molecules. Two-step syntheses "Roche" ester methyl methacrylate (79%; er 99:1), arguably widely used fragment polyketide synthesis, tropic (∼80% yield; ∼93:7), which potential several medicinally important classes compounds, illustrate power methods. Mechanistic studies confirm requirement a cationic Co(I) species [(

Язык: Английский

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Hydrogen Source Tuned Regiodivergent Asymmetric Hydroalkylations of 2‐Substituted 1,3‐Dienes with Aldehydes by Cobalt‐Catalysis

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(23)

Опубликована: Апрель 3, 2024

Abstract Catalytic methods allowing for the reliable prediction and control of diverse regioselectivity along with enantioselectivity to access different regio‐ enantiomers by switching least reaction parameters are one most attractive ways in organic synthesis, which provide enantioenriched architectures from identical starting materials. Herein, a Co‐catalyzed regiodivergent enantioselective reductive hydroalkylation 1,3‐dienes aldehydes has been achieved, furnishing homoallylic alcohol good levels enantioselectivity. The features switch tuned selection proton source. use an acid as source provided asymmetric 1,2‐hydroalkylation products under conditions, yet 4,3‐hydroalkylation were obtained silane hydride This catalytic protocol allows alcohols two continuous saturated carbon centers regio‐, diastereo‐,

Язык: Английский

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Chiral bisphosphine Ph-BPE ligand: a rising star in asymmetric synthesis

Chemical Society Reviews, Год журнала: 2024, Номер 53(13), С. 6735 - 6778

Опубликована: Янв. 1, 2024

The review summarizes the increasing applications of chiral bisphosphine ligand Ph-BPE in catalytic asymmetric reactions past twenty years.

Язык: Английский

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Theoretical investigation on cobalt-catalyzed hydroacylation reaction: Mechanism and origin of stereoselectivity

Molecular Catalysis, Год журнала: 2022, Номер 527, С. 112410 - 112410

Опубликована: Июнь 7, 2022

Язык: Английский

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Chemodivergent, Regio‐ and Enantioselective Cycloaddition Reactions between 1,3‐Dienes and Alkynes

Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(8)

Опубликована: Дек. 15, 2022

Alkynes and 1,3-dienes are among the most readily available precursors for organic synthesis. We report two distinctly different, catalyst-dependent, modes of regio- enantioselective cycloaddition reactions between these classes compounds providing rapid access to highly functionalized 1,4-cyclohexadienes or cyclobutenes from same precursors. Complexes an earth abundant metal, cobalt, with several commercially chiral bisphosphine ligands narrow bite angles catalyze [4+2]-cycloadditions a 1,3-diene alkyne giving cyclohexa-1,4-diene in excellent chemo-, enantioselectivities. In sharp contrast, complex finely tuned phosphino-oxazoline ligand promotes unique [2+2]-cycloaddition terminal double bond diene cyclobutene

Язык: Английский

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Chemodivergent Tandem Hydroalkylation and Hydroalkenoxylation of Conjugated Enynes

ACS Catalysis, Год журнала: 2024, Номер 14(13), С. 9742 - 9751

Опубликована: Июнь 14, 2024

Due to the instability and weak O-nucleophilicity of enol, carbonyl compounds prefer function as C-nucleophiles instead O-nucleophiles in extensively studied transition metal-catalyzed hydrofunctionalizations unsaturated bonds. The corresponding hydroalkenoxylation reaction has thus long been unexplored. Here, we describe a chemodivergent protocol for challenging reactions. Dictated by Pd catalyst bearing different ligands, both 5-exo-trig 6-endo-trig processes are demonstrated be feasible between 1,3-enynes ketoesters, polysubstituted hydrofurans hydropyrans achieved good yields excellent chemoselectivities. In addition, enantioselective is also explored under an Rh moderate efficiency but with high stereoselectivities. Mechanistic studies corroborate designed tandem hydroalkylation uncover that ligand-to-ligand hydrogen transfer process might involved turnover-limiting step hydroalkenoxylation.

Язык: Английский

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Stereoconvergent and Enantioselective Synthesis of Z-Homoallylic Alcohols via Nickel-Catalyzed Reductive Coupling of Z/E-1,3-Dienes with Aldehydes

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(32), С. 22157 - 22165

Опубликована: Авг. 5, 2024

Stereoconvergent reactions enable the transformation of mixed stereoisomers into well-defined, chiral products─a crucial strategy for handling

Язык: Английский

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Recent Advances in Non-Precious Metal Catalysis

Organic Process Research & Development, Год журнала: 2022, Номер 26(8), С. 2281 - 2310

Опубликована: Авг. 2, 2022

This review provides a summary of recently published developments in the field nonprecious metal catalysis (NPMC) and highlights range synthetic applications captured research between July October 2021. is an installment series on this area briefing Ni, Cu, Fe, Co catalysis. There has been evident increase publications NPMC, which indicates widespread interest among laboratories academia industry development utilization catalytic these metals.

Язык: Английский

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Asymmetric formal sp2-hydrocarbonations of dienes and alkynes via palladium hydride catalysis

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Окт. 9, 2023

Abstract Transition metal-catalyzed asymmetric hydrofunctionalizations of unsaturated bonds via π-ƞ 3 substitution have emerged as a reliable method to construct stereogenic centers, and mainly rely on the use heteroatom-based or carbon nucleophiles bearing acidic C-H bonds. In comparison, sp 2 are generally not under consideration because enormous challenges in cleaving corresponding inert Here, we report protocol achieve formal hydrocarbonations, including hydroalkenylation, hydroallenylation hydroketenimination both 1,3-dienes alkynes hydroalkylation Wittig reaction cascade. A series unachievable motifs hydrofunctionalizations, such di-, tri- tetra-substituted alkenes, allenes, tri-substituted ketenimines allyl skeletons all facilely constructed high regio-, diastereo- enantioselectivities with this cascade design. Stereodivergent synthesis four stereoisomers 1,4-diene stereocenter Z/E-controllable olefin unit highlights power present protocol. An interesting mechanistic feature is revealed that alkyne actually undergoes hydrocarbonation formation conjugated diene intermediate, different from conventional viewpoint hydrofunctionalization only involves allene species.

Язык: Английский

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