Asymmetric Formal Abnormal Claisen Rearrangement Enabled by Rh-Catalyzed Regio- and Enantioselective Allylic Alkylation

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(8), P. 5482 - 5490

Published: April 7, 2023

Abnormal Claisen rearrangement of phenyl allyl ether with the γ-alkyl group is longstanding. However, asymmetric version this named reaction has never been reported. Herein, a highly regio- and enantioselective allylic alkylation 4-hydroxycoumarin stereospecific Conia-ene/ene sequence developed as formal abnormal rearrangement. Chiral 4-hydroxycoumarins 3-allyl groups could be synthesized in up to 95% yield 96% ee under catalysis Rh chiral bioxazolinephosphine ligand. Experimental density functional theory calculation investigations support that based on reversible formation kinetically favored cis-disubstituted spirocyclopropane intermediate.

Language: Английский

---

Synthesis of Allenes by Hydroalkylation of 1,3-Enynes with Ketones Enabled by Cooperative Catalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(39), P. 21638 - 21645

Published: Sept. 22, 2023

A method for the synthesis of allenes by addition ketones to 1,3-enynes cooperative Pd(0)Senphos/B(C6F5)3/NR3 catalysis is described. wide range aryl- and aliphatic undergo various in high yields at room temperature. Mechanistic investigations revealed a rate-determining outer-sphere proton transfer mechanism, which was corroborated DFT calculations.

Language: Английский

---

Enantioselective Synthesis of Functionalized Arenes by Nickel‐Catalyzed Site‐Selective Hydroarylation of 1,3‐Dienes with Aryl Boronates

Angewandte Chemie, Journal Year: 2020, Volume and Issue: 132(33), P. 14174 - 14179

Published: May 6, 2020

Abstract A catalytic method for the site‐selective and enantioselective synthesis of functionalized arenes by intermolecular hydroarylation terminal internal 1,3‐dienes with aryl pinacolato boronates is reported. The reactions are promoted 5.0 mol % a readily available monodentate phosphoramidite‐Ni complex in ethanol, affording variety enantioenriched products up to 96 yield 99:1 er. Mechanistic studies indicate that Ni–allyl formation irreversible related nature arylboronate.

Language: Английский

---

Acyclic Quaternary Carbon Stereocenters through Transition-Metal-Catalyzed Enantioselective Functionalization of Unsaturated Hydrocarbons

Synthesis, Journal Year: 2022, Volume and Issue: 54(09), P. 2103 - 2118

Published: March 1, 2022

Abstract Acyclic quaternary carbon stereocenters occur frequently in natural products, bioactive molecules, and pharmaceutical compounds. Construction of a stereogenic center attached to four different carbons with defined spatial arrangement is daunting challenge asymmetric catalysis. Significant efforts have been directed towards the stereoselective construction such acyclic stereocenters. In particular, catalytic generation through functionalization unsaturated hydrocarbons an extremely attractive approach because are easily accessible both industry organic synthesis. this short review, we summarize recent advances achieved research area, aim inspire future development. 1 Introduction 2 Quaternary Carbon Stereocenters Functionalization Allenes 3 Dienes 4 Mono-alkenes 5 Alkynes 6 Summary Outlook

Language: Английский

---

Stereoselective Synthesis of Polysubstituted Dihydropyrroles via 1,5‐Addition and N‐1,4‐Addition Cascade

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(38)

Published: May 3, 2024

An unprecedented 1,5-addition/N-1,4-addition cascade reaction is established via palladium hydride catalysis. A variety of polysubstituted dihydropyrrole skeletons are constructed in high yield and with exclusively >20 : 1 diastereoselectivity. enantioselective protocol this design also developed to provide a novel access enantioenriched dihydropyrroles.

Language: Английский

---