Mn‐Catalyzed Dehydrocyanative Transannulation of Heteroarenes and Propargyl Carbonates through C−H Activation: Beyond the Permanent Directing Effects of Pyridines/Pyrimidines

Zheng, Guangfan; Sun, Jiaqiong; Xu, Youwei; Zhai, Shuailei; Li, Xingwei

doi:10.1002/anie.201900166

Cited by 52 publications

(19 citation statements)

References 102 publications

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“…Independent studies by the groups of Li and Ackermann revealed Mn(I)‐catalyzed dehydrocyanative domino reactions of 1‐(2‐pyridyl)‐2‐pyridones with propargyl carbonates involving C6−H allenylation. Subsequent Diels‐Alder reactions of the allenyl intermediate on the pyridine followed by retro‐Diels‐Alder and loss of HCN generated fused carbo/heterocycles (Scheme 1a, path C) [8c,d] . Recently, Ackermann and co‐workers reported the reaction of 1‐(2‐pyridyl)‐2‐pyridones with propargyl carbonates under Cp*Co(III) catalysis proceeded through a domino C6−H activation/pyridine directing group migration/alkyne annulation sequence to provide indolizinones (Scheme 1a, path D) [8e] …”

Section: Introductionmentioning

confidence: 99%

Rhodium(III)‐Catalyzed C−H Bond Functionalization of 2‐Pyridones with Alkynes: Switchable Alkenylation, Alkenylation/Directing Group Migration and Rollover Annulation

Luo

Zhao

et al. 2021

Chemistry A European J

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Cp*Rh(III)‐catalyzed chelation‐assisted direct C−H bond functionalization of 1‐(2‐pyridyl)‐2‐pyridones with internal alkynes that can be controlled to give three different products in good yields has been realized. Depending on the reaction conditions, solvents and additives, the reaction pathway can be switched between alkenylation, alkenylation/directing group migration and rollover annulation. These reaction manifolds allow divergent access to a variety of valuable C6‐alkenylated 1‐(2‐pyridyl)‐2‐pyridones, (Z)‐6‐(1,2‐diaryl‐2‐(pyridin‐2‐yl)vinyl)pyridin‐2(1H)‐ones and 10H‐pyrido[1,2‐a][1,8]naphthyridin‐10‐ones from the same starting materials. These protocols exhibit excellent regio‐ and stereoselectivity, broad substrate scope, and good tolerance of functional groups. A combination of experimental and computational approaches have been employed to uncover the key mechanistic features of these reactions.

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Section: Introductionmentioning

confidence: 99%

Rhodium(III)‐Catalyzed C−H Bond Functionalization of 2‐Pyridones with Alkynes: Switchable Alkenylation, Alkenylation/Directing Group Migration and Rollover Annulation

Luo

Zhao

et al. 2021

Chemistry A European J

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“…Recently, the involvement of directing groups into the substrate became one of the most promising, effective, and convenient methodologies to achieve highly regio–/stereoselective activation of C–H bonds . For instance, various directing groups, such as ketones, amide, and pyridine, have been applied in selective activation of benzylic C–H bonds and electronically activated alkyl C–H bonds. However, enantioselective functionalization of unbiased methylene C(sp 3 )–H bonds still represents a formidable challenge that is likely due to similar chemical properties and reaction mechanistic complexity in which subtle changes to the catalyst, substrate, and/or the reaction conditions can alter the reaction stereochemistry .…”

Section: Introductionmentioning

confidence: 99%

Unveiling the Mechanism, Origin of Stereoselectivity, and Ligand-Dependent Reactivity in the Pd(II)-Catalyzed Unbiased Methylene C(sp³)–H Alkenylation–Aza-Wacker Cyclization Reaction

et al. 2020

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The mechanism, origin of stereoselectivity, and ligand-dependent reactivity of Pd(II)-catalyzed methylene C(sp 3 )−H alkenylation−aza−Wacker cyclization to form (E)-β-stereogenic γ-lactam have been comprehensively studied by density functional theory (DFT) calculations. The calculated results reveal that the methylene C−H activation assisted by K 2 CO 3 via the concerted metalation− deprotonation mechanism is found to be the most preferred pathway, where the enantioselectivity is distinguished by the orientation of the methyl group of a substrate relative to a chiral ligand. However, the stereochemistry of the olefin moiety in the generated product is mainly determined by the oxidative addition step, where the coulombic interaction and dispersion effect differentiate the energy difference of diastereomeric transition states. In terms of the agostic interaction nature of "three-center two-electron" transition states, the discrepancy of reactivities caused by different Pd catalysts is attributed to the electron induction effect of substituents on the chiral ligands. In other words, the use of an electron-withdrawing group (e.g., −CN) in place of an electron-donating group (e.g., −OMe) enhances the oxidation state of the Pd atom and lowers vacant d orbitals of the palladium atom of the catalyst and in turn facilitates a larger amount of σ-electronic-charge injection into an empty 3d shell of the palladium center. Thus, the higher catalytic activity of the Pd catalyst with ligands substituted by an electron-withdrawing group is anticipated.

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“…[14] Moreover,synthesis of 3qq at a2 .5 mmol scale was realized in 71 %y ield. 2-Pyridones functionalized with various electron-donating (OMe,O Bn, NHPh), electron-withdrawing (CF 3 ), alkenyl, and halogen groups at the 3-, 4-, and 5-postions were all effective substrates (3ba-3 oa), generating the products in moderate to high yields.T he compatibility with a5 -alkenyl group indicates tolerance of steric effects.…”

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confidence: 99%

“…Thecoupling of 2-pyridone 1d and ester 2a (80 8 8C, 1h)a fforded organomanganese complex 8, [14] together with as mall amount of coupled product 3da,thus suggesting that 8 is likely aresting state of the catalyst (Scheme 6a). Thecoupling of 2-pyridone 1d and ester 2a (80 8 8C, 1h)a fforded organomanganese complex 8, [14] together with as mall amount of coupled product 3da,thus suggesting that 8 is likely aresting state of the catalyst (Scheme 6a).…”

mentioning

confidence: 99%