Enantioconvergent Hydroboration of E/Z-Mixed Trisubstituted Alkenes

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(30), P. 21089 - 21098

Published: July 12, 2024

The lack of mode for chirality recognition makes it particularly challenging to carry out asymmetric transformations on

Language: Английский

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Rhodium-Catalyzed Highly Enantioselective Hydroboration of Acyclic Tetrasubstituted Alkenes Directed by an Amide

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(23), P. 16194 - 16202

Published: June 4, 2024

Although progress has been made in enantioselective hydroboration of di- and trisubstituted alkenes over the past decades, tetrasubstituted with high diastereo- enantioselectivities continues as an unmet challenge since 1950s due to its extremely low reactivity difficulties simultaneously control regio- stereoselectivity a alkene. Here, we report highly regio-, diastereo-, catalytic diverse acyclic alkenes. The delicate interplay electron-rich rhodium complex coordination-assistance forms adaptive catalyst that effectively overcomes controls stereoselectivity. generality system is exemplified by efficacy across various steric electronic properties.

Language: Английский

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Synthesis of Some New Chiral Triazole-oxazoline Derivatives

Current Organic Synthesis, Journal Year: 2024, Volume and Issue: 22(1), P. 136 - 142

Published: July 12, 2024

: Some new (S)-2-[1-aryl-5-methyl-1H-1,2,3-triazol-4-yl]-4-benzyl-4,5-dihydro-ox-azoline were synthesized by the reaction of (S)-N-(1-hydroxy-3-phenylpropan-2-yl)-1-aryl-5-methyl-1H-1,2,3-triazole-4-carboxamides which prepared from aromatic amine as start-ing materials, with p-toluenesulfonyl chloride, triethylamine and DMAP. The structures characterized 1H NMR, 13C MS IR. chiral triazole-oxazoline was used a ligand in Diels-Alder asymmetric catalytic between 3-allyl-1,3-ox-azolidin-2-ketone 2-methyl-1,3-butadiene, using PdCl2 catalyst. (S)-3-(4-methylcyclo-hexe-3-ene-1-formyl)-1,3-oxazolidin-2-one obtained. Background: ligands are rarely reported. Objective: aim study to synthsize some (S)-4-benzyl-2-(1-aryl-5-methyl-1H-1,2,3-triazole-4-yl)-4,5-dihydrooxazoline (5a-g). Methods: one-pot methods oriented synthesis adopted. This provides sim-ple effective method for derivatives. Results: (5a-g) cyclization 3-allyl-1,3-oxazolidin-2-ketone 2-methyl-1,3-butadiene catalyzed (S)-4-triazole-oxazoline ligands. Conclusion: (S)-4-benzyl-2-(1-aryl-5-methyl-1H-1,2,3-triazole-4-yl)-4,5-dihydro-oxazoline corresponding N-[(S)-1-hydroxy-3-phenylpropan-2-yl]-1-aryl-5-methyl-1H-1,2,3-triazole-4-formamide, through method. After preliminary evaluation, triazoline-oxazoline ligands, 1,2,3-triazole rings, like pyridine-type materials saved replace one oxazoline ring di-oxazoline reactions.

Language: Английский

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Cationic Bis(η⁶-arene) Cobalt(I) Complexes: Enabling Catalyst Discovery by High-Throughput Experimentation

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(17), P. 13260 - 13268

Published: Aug. 20, 2024

Cationic, 20-electron bis(η6-arene)Co(I) complexes have been synthesized and evaluated as precursors for the generation of bis(phosphine) cobalt(I) η6-arene precatalysts. The arenes anions in were varied, with isolated examples, including [Al(pftb)4]− (pftb = (CF3)3CO), [BArF4]− (tetrakis[3,5-bis(trifluoromethyl)phenyl]borate), [SbF6]−. Treatment a series bis(phosphines) resulted arene displacement isolation well-defined [(bis(phosphine))Co(η6-arene)][X] (X Al(pftb)4– SbF6–; C6H6, C6H5Me, C6H5Et) 84–99% yield. This ligand substitution enabled unprecedented catalyst libraries using high-throughput experimentation (HTE) asymmetric alkene hydrogenation, well formal [2 + 2] cycloaddition, hydroboration, C(sp2)–H functionalization. These versatile simplify increasingly complex chemical transformations by introducing single-component, precatalysts through general substitution.

Language: Английский

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Cobalt-Catalyzed Three-Component Alkyl Arylation of Acrylates with Alkyl Iodides and Aryl Grignard Reagents

Organic Letters, Journal Year: 2024, Volume and Issue: 26(43), P. 9288 - 9293

Published: Oct. 21, 2024

A highly regioselective cobalt-catalyzed three-component alkyl arylation of acrylates with iodides and aryl Grignard reagents has been established. The reaction efficiently provides an alternative strategy for the construction α-aryl esters a broad substrate scope good yields under mild conditions. practical applicability this protocol is shown by scaled-up further transformations products. In addition, preliminary mechanistic explorations demonstrated that radicals generated efficient cobalt catalysis are instantaneously added to finally afford desired

Language: Английский

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Five-membered ring systems with O and N atoms

Progress in heterocyclic chemistry, Journal Year: 2024, Volume and Issue: unknown, P. 275 - 308

Published: Jan. 1, 2024

Language: Английский

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