Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(5), P. 1366 - 1371
Published: Jan. 1, 2024
A regio- and stereoselective hydroamidation of allenes using diisobutylaluminum hydride isocyanates is described, resulting in the formation α-quaternary amides.
Language: Английский
Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(49)
Published: Oct. 17, 2023
Abstract An enantioselective carbene‐catalyzed radical‐radical coupling of acyl imidazoles and racemi c Hantzsch esters is disclosed. This method involves the an N‐heterocyclic carbene‐derived ketyl radical a secondary sp 3 ‐carbon allows access to chiral α‐aryl aliphatic ketones in moderate‐to‐good yields enantioselectivities without any competitive epimerization. The utility this protocol highlighted by late‐stage functionalization various pharmaceutical compounds further demonstrated transformation enantioenriched products biologically relevant molecules. Computational investigations reveal carbene controls double‐facial selectivity alkyl radicals, respectively.
Language: Английский
Citations
29
Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 57(9), P. 2441 - 2444
Published: Dec. 14, 2017
Vinyl boron ate complexes of enantioenriched secondary alkyl pinacolboronic esters undergo stereospecific radical-induced 1,2-migration in radical polar crossover reactions. In this three-component process various commercially available iodides act as precursors and light is used for chain initiation. Subsequent oxidation protodeborylation leads to valuable α-chiral ketones chiral alkanes, respectively, with excellent enantiopurity.
Language: Английский
Citations
84
Journal of the American Chemical Society, Journal Year: 2017, Volume and Issue: 139(36), P. 12394 - 12397
Published: Aug. 27, 2017
The first example of palladium(II)-catalyzed β-C(sp3)-H iodination a wide range ketones using commercially available aminooxyacetic acid auxiliary has been achieved. This L, X-type directing group overcomes the limitations transient approach for C(sp3)-H functionalization ketones. Practical advantages this method include simple installation without chromatography, exceptional tolerance α-functional groups, as well alkenes and alkynes, rapid access to diverse sterically hindered quaternary centers.
Language: Английский
Citations
75
ACS Catalysis, Journal Year: 2019, Volume and Issue: 9(4), P. 3104 - 3143
Published: Feb. 25, 2019
This review comprises two major parts, which have chiral metal enolates as their focus. In the first part, we discuss transition-metal-catalyzed conjugate additions leading to enolates, are then subsequently functionalized by reactions with electrophiles, both further catalyzed or uncatalyzed. The second part deals base-generated and use in asymmetric processes.
Language: Английский
Citations
63
Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(36), P. 12558 - 12562
Published: July 2, 2019
Abstract Hydrogen borrowing catalysis serves as a powerful alternative to enolate alkylation, enabling the direct coupling of ketones with unactivated alcohols. However, date, methods that enable control over absolute stereochemical outcome such process have remained elusive. Here we report catalytic asymmetric method for synthesis enantioenriched cyclohexanes from 1,5‐diols via hydrogen catalysis. This reaction is mediated by addition chiral iridium(I) complex, which able impart high levels enantioselectivity upon process. A series been prepared and mode enantioinduction has probed combination experimental DFT studies.
Language: Английский
Citations
57
Science, Journal Year: 2021, Volume and Issue: 374(6568), P. 734 - 740
Published: Nov. 4, 2021
Careful choreography for a ketone shift Chemists devote tremendous effort to the precise placement of oxygens in molecular frameworks. Wu et al . report convenient method oxygen carbonyl group an adjacent carbon center. After activation alkenyl triflate, cooperative catalysis by palladium and norbornene adds nitrogen neighboring while displacing triflate with hydride. Hydrolysis then produces desired shifted ketone. The protocol is well suited late-stage variation complex molecules during drug optimization. —JSY
Language: Английский
Citations
44
Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(41)
Published: Aug. 22, 2022
Late-stage methylation is a key technology in the development of pharmaceutical compounds. Methyltransferase biocatalysis may provide powerful options to insert methyl groups into complex molecules with high regio- and chemoselectivity. The challenge large-scale application methyltransferases their dependence on S-adenosylmethionine (SAM) as stoichiometric, thus exceedingly expensive co-substrate. As solution this problem, we others have explored use halides reagents for situ regeneration SAM. However, need handle volatile electrophiles, such iodide (MeI), also hamper applications at scale. more practical solution, now developed an enzyme-catalyzed process SAM toluene sulfonate. Herein, describe enzymes from thiopurine methyltransferase family that accept sulfate- sulfonate-based donors convert S-adenosylhomocysteine efficiencies rival MeI-based reactions.
Language: Английский
Citations
36
Angewandte Chemie, Journal Year: 2019, Volume and Issue: 131(47), P. 17010 - 17014
Published: Sept. 18, 2019
Abstract Photochemical enantioselective nickel‐catalyzed cross‐coupling reactions are difficult to implement. We report a visible‐light‐mediated strategy that successfully couples symmetrical anhydrides and 4‐alkyl dihydropyridines (DHPs) afford enantioenriched α‐substituted ketones under mild conditions. The chemistry does not require exogenous photocatalysts. It is triggered by the direct excitation of DHPs, which act as radical source reductant, facilitating turnover chiral catalytic nickel complex.
Language: Английский
Citations
52
Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(1)
Published: Nov. 21, 2023
The direct α-alkylation of acyclic carbonyls with nonactivated hydrocarbons through C(sp3 )-H functionalization is both extremely promising and notably challenging, especially when attempting to achieve enantioselectivity using iron-based catalysts. We have identified a robust chiral iron complex for the oxidative cross-coupling 2-acylimidazoles benzylic allylic hydrocarbons, as well alkanes. readily available tunable N,N'-dioxide catalysts in connection oxidants exhibit precise asymmetric induction (up 99 % ee) good compatibility moderate yields 88 yield). This protocol provides an elegant straightforward access optically active carbonyl derivatives starting from simple alkanes without prefunctionalization. Density functional theory (DFT) calculations control experiments were made gain insight into nature C-C bond formation origin enantioselectivity. propose radical-radical process enabled by immediate interconversion between ferric species ferrous species.
Language: Английский
Citations
14
Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(36), P. 19542 - 19553
Published: Aug. 28, 2023
Cu-catalyzed highly stereoselective and enantiodivergent syntheses of (Z)- or (E)-β,γ-unsaturated ketones from 1,3-butadienyl silanes are developed. The nature the silyl group dienes has a significant impact on stereo- enantioselectivity reactions. Under developed catalytic systems, reactions acyl fluorides with phenyldiemthylsilyl-substituted 1,3-diene gave (Z)-β,γ-unsaturated bearing an α-tertiary stereogenic center excellent enantioselectivities high Z-selectivities, where triisopropylsilyl-substituted 1,3-butadiene formed optical purities E-selectivities. products generated contain three functional groups orthogonal chemical reactivities, which can undergo variety transformations to afford synthetically valuable intermediates.
Language: Английский
Citations
13