Palladium‐Catalyzed Decarboxylative Benzylation and Allylation of Six‐MemberedEndocyclic Enecarbamates DOI Open Access

Junhao Ruan,

Xi Cao, Yipeng Zhou

et al.

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 16, 2024

Abstract Six‐membered endocyclic benzyl/allyl enecarbamates undergo a Pd‐catalyzed decarboxylation process to generate 1‐azaallyl anions and Pd–benzyl/allyl cations. The ion pair then react with each other followed by reduction ultimately give unprotected 2‐(hetero)aryl‐3‐benzylpiperidines 2‐(hetero)aryl‐3‐allylpiperidines in 31–91% yields as single cis ‐diastereomers. These reactions represent strategy form β ‐substituted piperidines, which generates elusive anion intermediates introducing the negative charge from N‐terminal.

Language: Английский

P-Stereogenic Phosphorus Ligands in Asymmetric Catalysis DOI
Tsuneo Imamoto

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(14), P. 8657 - 8739

Published: July 2, 2024

Chiral phosphorus ligands play a crucial role in asymmetric catalysis for the efficient synthesis of useful optically active compounds. They are largely categorized into two classes: backbone chirality and P-stereogenic ligands. Most reported belong to former class. Privileged ones such as BINAP DuPhos frequently employed wide range catalytic transformations. In contrast, latter class has remained small family many years mainly because their synthetic difficulty. The late 1990s saw emergence novel with superior enantioinduction ability Rh-catalyzed hydrogenation reactions. Since then, numerous have been synthesized used This Review summarizes thus far, including stereochemical electronic properties that afford high excellent enantioselectivities. Examples reactions use this described together applications construction key intermediates natural products therapeutic agents. literature covered dates back 1968 up until December 2023, centering on studies published later years.

Language: Английский

Citations

42
Dual Relay Rh-/Pd-Catalysis Enables β-C(sp3)-H Arylation of α-Substituted Amines DOI Creative Commons
Shuailong Li, Sani Yahaya, Jan Bojanowski

et al.

Chemical Science, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

A dual relay catalytic protocol, built on reversible dehydrogenation of amines by Rh catalysis and C-H functionalisation transient imines Pd catalysis, is reported to enable regioselective arylation at their unactivated β-C(sp3)-H bond. Notably, the new strategy applicable secondary anilines N-PMP-protected primary aliphatic intermediate steric demands, which in contrast existing strategies that involve either free-amine-directed activation for highly sterically hindered or steric-controlled migrative cross-coupling unhindered N-Boc protected amines. Regioselectivity reaction imposed electronic effects imine intermediates rather than between specific starting materials catalysts, thereby opening uncharted scope In a broader sense, this study demonstrates opportunities involving hydrogen borrowing chemistry, previously explored alcohols, execute otherwise challenging transformations amines, commonly present natural products, pharmaceuticals, biologically active molecules, functional materials.

Language: Английский

Citations

1
Catalysis and Synthesis Enabled by P-Chiral Dihydrobenzooxaphosphole Ligands DOI
Zhen Cao, Dongyang He, Wenjun Tang

et al.

Organic Process Research & Development, Journal Year: 2024, Volume and Issue: 28(4), P. 949 - 977

Published: April 8, 2024

P-Chiral phosphorus ligands received little attention in organic chemistry until Knowles made his landmark contribution asymmetric hydrogenation by developing the P-chiral CAMP and DIPAMP. The development of accelerated end last century with advent some highly efficient renowned for hydrogenation, including BisP*, TangPhos, QuinoxP*, DuanPhos, et al. However, most reported were air-sensitive, difficult to make, or lacked structural modularity, hampering their availability applicability. sterically electronically tunable is particularly desirable. Over past decade, a family hindered, electron-rich, structurally tunable, air-stable dihydrobenzooxaphosphole emerged that proved be versatile various transformations. 5 years witnessed an increasing number studies related these discovery unprecedented catalytic properties This review highlights unique catalysis applications synthesis natural products therapeutic agents.

Language: Английский

Citations

5
B(C6F5)3-Catalyzed C(sp3)–H Alkylation of Tertiary Amines with Electron-Deficient Olefins: Determinants of Site Selectivity DOI

Xin-Yue Zhou,

Yingbo Shao,

Ruiting Guo

et al.

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(10), P. 8041 - 8049

Published: May 8, 2024

The reason for the site selectivity previously reported B(C6F5)3-catalyzed C(sp3)–H alkylation of tertiary amines with electron-deficient olefins remains a mystery. appears to be governed by number electron-withdrawing groups (EWGs) on olefin: one EWG results in α-alkylation, whereas two EWGs (one each end double bond) result β-alkylation. In this study, we solved mystery and unlocked pathway β-alkylation bearing only EWG. Control experiments density functional theory calculations provided detailed picture reaction mechanism both α- Furthermore, demonstrated broad scope reaction.

Language: Английский

Citations

4
Modular Construction of Chiral Aminopiperidine via Palladium-Catalyzed Hydroamination of 1,2-Dihydropyridine DOI
Qian Wang, Shouyou Huang,

Lifei Nie

et al.

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 12, 2025

In this study, we describe a generally straightforward methodology for the catalytic synthesis of chiral aminopiperidine from pyridine and azoles. The key step was palladium-catalyzed regioselective N–H insertion into double bond 1,2-dihydropyridine. This hydroamination exhibits wide substrate scope functional group compatibility. Mechanistic study revealed that C═C followed cis addition. utility protocol demonstrated by diverse functionalization enamine bond.

Language: Английский

Citations

0
Palladium-Catalyzed Allylation of Endocyclic 1-Azaallyl Anions DOI
Xiaoyu Yang, Biao Zhang,

Junhao Ruan

et al.

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(12), P. 8896 - 8905

Published: June 10, 2024

Endocyclic 1-azaallyl anions engage allyl acetates in a palladium-catalyzed allylation followed by reduction to give unprotected 2-(hetero)aryl-3-allylpiperidines and 2-allyl-3-arylmorpholines, products not easily accessible other means. The group is then readily transformed into variety of functional groups. Preliminary studies on the asymmetric variant reaction using an enantiomerically pure BI-DIME-type ligand provide product with moderate enantioselectivity. Computational suggest that energy barriers inner-sphere reductive elimination outer-sphere nucleophilic substitution are almost same, which makes both them possible pathways. In addition, mechanism displays enantiodiscriminating C–C bond forming step, while much less selective, combined

Language: Английский

Citations

1
Palladium‐Catalyzed Decarboxylative Benzylation and Allylation of Six‐MemberedEndocyclic Enecarbamates DOI Open Access

Junhao Ruan,

Xi Cao, Yipeng Zhou

et al.

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 16, 2024

Abstract Six‐membered endocyclic benzyl/allyl enecarbamates undergo a Pd‐catalyzed decarboxylation process to generate 1‐azaallyl anions and Pd–benzyl/allyl cations. The ion pair then react with each other followed by reduction ultimately give unprotected 2‐(hetero)aryl‐3‐benzylpiperidines 2‐(hetero)aryl‐3‐allylpiperidines in 31–91% yields as single cis ‐diastereomers. These reactions represent strategy form β ‐substituted piperidines, which generates elusive anion intermediates introducing the negative charge from N‐terminal.

Language: Английский

Citations

0