A DFT Study on the NHC-Catalyzed Reaction of Enals with Aminoacrylates: Mechanism, Regioselectivity, and Stereoselectivity DOI
Yan Li, Junjie Xiao,

Yanlong Kang

и другие.

The Journal of Physical Chemistry A, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 27, 2024

DFT (M06-2X) calculations were used to study the NHC-catalyzed [3 + 3] cycloaddition of enals with aminoacrylates. The catalytic cycle begins binding NHC enal. Subsequent intramolecular proton transfer generates Breslow intermediate. This intermediate undergoes an oxidative reaction, leading formation acyl azolium intermediate, which further reacts other substrate aminoacrylate via a new C–C bond formation. step determines stereoselectivity current and re-face addition mode S-configuration is predominant. Afterward, sequential protonation, deprotonation, cyclization form six-membered cyclic upon elimination affords final product dihydropyridinone. computed enantiomeric excess (99.1% ee) in very good agreement experimentally reported value (99% ee). origin enantioselectivity traced stronger LP···π interactions between favored S-congurational transition state.

Язык: Английский

Mechanism and Origin of Stereoselectivity of N-Heterocyclic Carbene (NHC)-Catalyzed Transformation Reaction of Benzaldehyde with o-QDM as Key Intermediate: A DFT Study DOI

Yilu Luo,

M. Zhao, Yang Wang

и другие.

The Journal of Physical Chemistry A, Год журнала: 2024, Номер 128(30), С. 6190 - 6198

Опубликована: Июль 18, 2024

N-heterocyclic carbene (NHC)-bound

Язык: Английский

Процитировано

5

Mechanism and Origins of Regio- and Stereoselectivities of NHC-Catalyzed Dearomative Annulation of Benzoazoles and Cinnamaldehydes from DFT DOI
Yan Li,

Yanlong Kang,

Junjie Xiao

и другие.

The Journal of Physical Chemistry A, Год журнала: 2025, Номер unknown

Опубликована: Март 5, 2025

A theoretical study on the mechanism, regioselectivity, and enantioselectivity of NHC-catalyzed dearomatizing annulation benzoxazoles with enals has been conducted using density functional theory calculations. Our calculated results indicate that favored mechanism occurs through eight reaction steps: initial binding NHC to enals, followed by formation Breslow intermediate via proton transfer. Subsequent oxidation generates α,β-unsaturated acylazolium intermediate, which can undergo Michael addition benzoxazoles. Sequential protonation/deprotonation/cyclization produces six-membered cyclic undergoes catalyst elimination, leading final product. DABCO·H+ was found play important roles in transfer cyclization. Without DABCO·H+, energy barrier up 44.2 kcal/mol for step 2 is too high be accessible. With corresponding value lowered 18.6 kcal/mol. The cyclization 7.4 DABCO·H+. determines both regioselectivity. According NCI analysis, controlled strong interactions (such as C-H···O, C-H···N, π···π) between We also discuss solvent substituent effects role NHC. mechanistic insights obtained present would help improving current systems or designing new synthetic routes.

Язык: Английский

Процитировано

0

Chromium(III)-Catalyzed Desymmetrization of meso-Epoxides via Remote Stereocontrol: Synthesis of Chiral Fluorenes Bearing All-Carbon Quaternary Stereocenters DOI
Ying Zhou,

Feng Jiang,

Xin Yue

и другие.

Organic Letters, Год журнала: 2024, Номер 26(4), С. 877 - 882

Опубликована: Янв. 24, 2024

An asymmetric desymmetrization of fluorene-derived meso-epoxides is disclosed for the construction chiral fluorenes bearing an all-carbon quaternary stereocenter at C9. This catalyzed by a (salen)CrIII complex via remote stereocontrol, producing diverse with excellent yields and stereoselectivity. The practicality this protocol was demonstrated through transformation obtained products to some intriguing enantioenriched polymerizable monomers.

Язык: Английский

Процитировано

2

NHC-Catalyzed Cross-Coupling of Aldehydes for C(sp2)−O Bond Formation DOI Open Access
Yousuke Yamaoka, Hideto Miyabe

Опубликована: Март 7, 2024

In the past few decades, N-heterocyclic carbenes (NHCs) open new field of organocatalysis in synthetic organic chemistry. This review highlights dramatic progress NHC-catalyzed C−O bond formation based on activation aldehyde C(sp2)−H bonds. The oxidative and redox transformations for synthesis various molecules with structural diversity complexity are summarized. Furthermore, methods strategies NHC catalysis emerging continuously; thus, cooperative Brønsted acid, hydrogen-bonding catalyst, transition-metal photocatalyst is also described.

Язык: Английский

Процитировано

1

NHC-Catalyzed Reaction of Aldehydes for C(sp2)–O Bond Formation DOI Open Access
Yousuke Yamaoka, Hideto Miyabe

Catalysts, Год журнала: 2024, Номер 14(4), С. 219 - 219

Опубликована: Март 22, 2024

In the past few decades, N-heterocyclic carbenes (NHCs) have opened new field of organocatalysis in synthetic organic chemistry. This review highlights dramatic progress NHC-catalyzed C–O bond formation based on activation aldehyde C(sp2)–H bonds. The oxidative and redox transformations for synthesis various molecules with structural diversity complexity are summarized. Furthermore, methods strategies NHC catalysis emerging continuously; thus, cooperative Brønsted acid, hydrogen-bonding catalyst, transition-metal photocatalyst also described.

Язык: Английский

Процитировано

1

Mechanisms, regio- and stereoselectivities involved in NHC catalyzed dearomatizing annulation of ester with ylide: A computational study DOI
Yan Li, Junjie Xiao,

Yanlong Kang

и другие.

Molecular Catalysis, Год журнала: 2024, Номер 560, С. 114146 - 114146

Опубликована: Апрель 16, 2024

Язык: Английский

Процитировано

1

Catalytic Asymmetric Synthesis of Chiral Fluorenes: Recent Developments and Future Perspectives DOI

Tianyuan Ou,

Liming Xiang,

Ying Zhou

и другие.

European Journal of Organic Chemistry, Год журнала: 2024, Номер 27(46)

Опубликована: Авг. 26, 2024

Abstract The chiral fluorene fragment constitutes one of the most important scaffolds frequently found in numerous bioactive molecules, ligands, and advanced functional materials due to its unique physical properties. In this context, various transition metal‐ organo‐catalyzed asymmetric reactions have been developed prepare fluorenes with high optical purity. present mini‐review, we summarize fifteen years achievements catalytic synthesis their derivatives. Particular attention is given strategies used mechanistic aspects some significant reactions. Moreover, cutting‐edge developments silafluorenes are also highlighted.

Язык: Английский

Процитировано

0

Highly Enantioselective Synthesis of Polycyclic Dihydroisoquinolinones via NHC-Catalyzed [4 + 2] Annulations DOI
Xiaojie Ren, Xiaoyong Duan,

Yuxuan Feng

и другие.

The Journal of Organic Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Сен. 13, 2024

The NHC-catalyzed enantioselective [4 + 2] annulation of 9

Язык: Английский

Процитировано

0

One-pot synthesis of functionalized dihydropyridin-2-ones via carbene-catalyzed base-controlled [3+3] annulation reaction DOI
Zhan‐Yong Wang,

Guoyang Ma,

Yaoyao Xu

и другие.

Chemical Communications, Год журнала: 2024, Номер unknown

Опубликована: Янв. 1, 2024

Herein, we have described a novel organocatalytic approach to access biologically important dihydropyridin-2-ones in one-pot way with generally high yields (up 99%) and excellent enantioselectivities 99% ee). This reaction proceeded

Язык: Английский

Процитировано

0

Six-membered ring systems: With O and/or S atoms DOI
Clementina M.M. Santos, Artur M. S. Silva

Progress in heterocyclic chemistry, Год журнала: 2024, Номер unknown, С. 421 - 484

Опубликована: Янв. 1, 2024

Язык: Английский

Процитировано

0