Recent advances in the synthesis of chiral α-tertiary aminesviatransition-metal catalysis

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(28), P. 4099 - 4114

Published: Jan. 1, 2023

Recent progress in the assembly of chiral α-tertiary amines last decade via transition-metal catalysis is summarized.

Language: Английский

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Energy-Transfer-Enabled Regioconvergent Alkylation of Azlactones via Photocatalytic Radical–Radical Coupling

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(7), P. 4894 - 4902

Published: March 27, 2023

C-4-selective functionalization of azlactones provides access to α,α-disubstituted unnatural α-amino acids, which has been extensively investigated in the past decades. However, a vast majority such transformations are two-electron transfer reactions. Herein, leveraging on persistent radical effect, we develop photocatalytic energy transfer-enabled regioconvergent alkylation with redox-active esters via radical–radical couplings. This strategy is extended utilization simple alkanes as precursors, whereby aryl play dual role an oxidant and hydrogen-atom-transfer agent. Notably, excited state Ir(III) photocatalyst enables selective activation unwanted imine products through triplet transfer, delivering C-4-functionalized high regioselectivity. Both experimental investigations density functional theory calculations reaction mechanism were performed, supporting EnT-enabled coupling pathways.

Language: Английский

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Practical asymmetric amine nucleophilic approach for the modular construction of protected α-quaternary amino acids

Chemical Science, Journal Year: 2022, Volume and Issue: 13(23), P. 6806 - 6812

Published: Jan. 1, 2022

We report the first amine nucleophilic approach for modular construction of enantioenriched protected α-quaternary amino acids. The key to success is use an alcohol solvent, which makes a rationally designed COOMe-bonded Cu-allenylidene electrophilic intermediate stable enough couple with nucleophiles before its decomposition. reaction features wide functional group tolerance high enantioselectivity, typically >90% ee, and amenable modification commercially available bioactive molecules. resultant α-amino acids could be readily converted into number precious amines featuring α-hindered tertiary carbon centers, are otherwise synthetically quite challenging, including those aldehyde, peptides or α-vinyl ester >92% ee in excellent yields. This protocol utilized synthesis α-ethylnorvaline 3 steps, significant advancement comparison 11-step sequence reported previously.

Language: Английский

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Metal-free photoinduced C(sp3)–H/C(sp3)–H cross-coupling to access α‑tertiary amino acid derivatives

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Oct. 6, 2023

The cross-dehydrogenative coupling (CDC) reaction is the most direct and efficient method for constructing α-tertiary amino acids (ATAAs), which avoids pre-activation of C(sp3)-H substrates. However, use transition metals harsh conditions are still significant challenges these reactions that urgently require solutions. This paper presents a mild, metal-free CDC construction ATAAs, compatible with various benzyl C-H substrates, functionalized alkyl good regioselectivity. Notably, our exhibits excellent functional group tolerance late-stage applicability. According to mechanistic studies, one-step synthesized bench-stable N-alkoxyphtalimide generates highly electrophilic trifluoro ethoxy radical serves as key intermediate in process acts hydrogen atom transfer reagent. Therefore, additive-free offers promising strategy synthesis ATAAs under mild conditions.

Language: Английский

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Research Progress in the Synthesis of α-Tertiary Amines via Radical Strategies

Chinese Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: 45(1), P. 22 - 22

Published: Jan. 1, 2025

Language: Английский

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