Brønsted Acid Catalyzed Dearomatization by Intramolecular Hydroalkoxylation/Claisen Rearrangement: Diastereo‐ and Enantioselective Synthesis of Spirolactams DOI
Pengfei Chen, Bo Zhou, Peng Wu

et al.

Angewandte Chemie, Journal Year: 2021, Volume and Issue: 133(52), P. 27370 - 27376

Published: Oct. 21, 2021

Abstract Described herein is a novel Brønsted acid catalyzed intramolecular hydroalkoxylation/Claisen rearrangement, allowing the practical and atom‐economic synthesis of range valuable spirolactams from readily available ynamides in generally good to excellent yields with diastereoselectivities broad substrate scope. Importantly, an unexpected dearomatization nonactivated arenes heteroaromatic compounds involved this tandem sequence. Moreover, asymmetric version cyclization was also achieved by efficient kinetic resolution chiral phosphoric catalysis. In addition, [3,3]‐rearrangement shown be kinetically preferred over related [1,3]‐rearrangement theoretical calculations.

Language: Английский

Fused-Ring-Linked Covalent Organic Frameworks DOI
Jie Feng, Yajie Zhang, Shenghua Ma

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(14), P. 6594 - 6603

Published: April 5, 2022

The development of linkage chemistry in the research area covalent organic frameworks (COFs) is fundamentally important for creating robust structures with high crystallinity and diversified functionality. We reach herein a new level complexity controllability by achieving first synthesis fused-ring-linked COFs. A series bicyclic pyrano[4,3-b]pyridine COFs have been constructed via cascade protocol involving Schiff-base condensation, intramolecular [4 + 2] cycloaddition, dehydroaromatization. With broad scope Brønsted or Lewis acids as catalyst, designed monomers, that is, O-propargylic salicylaldehydes multitopic anilines, were converted into one-pot fashion. obtained exhibited excellence terms purity, stability, crystallinity, comprehensively characterized solid-state nuclear magnetic resonance (NMR) spectroscopy, powder X-ray diffraction, high-resolution transmission electron microscopy, so on. Specifically, highly selective formation (>94%) was verified quantitative NMR measurements combined 13C-labeling synthesis. Moreover, fused-ring possesses fully locked conformation, which benefits to observed these Advancing from solo bonds single rings fused rings, this study has opened up possibilities concise construction sophisticated COF controllability.

Language: Английский

Citations

80
Brønsted Acid Catalyzed Dearomatization by Intramolecular Hydroalkoxylation/Claisen Rearrangement: Diastereo‐ and Enantioselective Synthesis of Spirolactams DOI
Pengfei Chen, Bo Zhou, Peng Wu

et al.

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(52), P. 27164 - 27170

Published: Oct. 21, 2021

Described herein is a novel Brønsted acid catalyzed intramolecular hydroalkoxylation/Claisen rearrangement, allowing the practical and atom-economic synthesis of range valuable spirolactams from readily available ynamides in generally good to excellent yields with diastereoselectivities broad substrate scope. Importantly, an unexpected dearomatization nonactivated arenes heteroaromatic compounds involved this tandem sequence. Moreover, asymmetric version cyclization was also achieved by efficient kinetic resolution chiral phosphoric catalysis. In addition, [3,3]-rearrangement shown be kinetically preferred over related [1,3]-rearrangement theoretical calculations.

Language: Английский

Citations

70
Copper‐Catalyzed Asymmetric Diyne Cyclization via [1,2]‐Stevens‐Type Rearrangement for the Synthesis of Chiral Chromeno[3,4‐c]pyrroles DOI

Feng‐Lin Hong,

Chong‐Yang Shi,

Pan Hong

et al.

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 61(7)

Published: Dec. 14, 2021

Here, we report a copper-catalyzed asymmetric cascade cyclization/[1,2]-Stevens-type rearrangement via non-diazo approach, leading to the practical and atom-economic assembly of various valuable chiral chromeno[3,4-c]pyrroles bearing quaternary carbon stereocenter in generally moderate good yields with wide substrate scope excellent enantioselectivities (up 99 % ee). Importantly, this protocol not only represents first example catalytic [1,2]-Stevens-type based on alkynes but also constitutes formal carbene insertion into Si-O bond.

Language: Английский

Citations

63
Enantioselective Copper‐Catalyzed Formal [2+1] and [4+1] Annulations of Diynes with Ketones via Carbonyl Ylides DOI
Linjun Qi,

Cui‐Ting Li,

Zheng‐Qi Huang

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(43)

Published: Aug. 17, 2022

Carbonyl ylides have proven to be powerful synthons for the efficient construction of various valuable O-heterocycles, and formation carbonyl by reaction metal carbenes with carbonyls has attracted increasing attention over past decades. However, a catalyst-controlled highly enantioselective from is extremely challenging. Herein, we report novel copper-catalyzed asymmetric formal [2+1] [4+1] annulations diynes ketones via ylides. Importantly, this protocol not only represents first example successful epoxidation ylides, but also constitutes vinyl cations compounds. This method leads divergent, practical atom-economical synthesis range chiral oxiranes dihydrofurans in moderate excellent yields generally enantioselectivities diastereoselectivities remote-stereocontrol strategy.

Language: Английский

Citations

43
Catalyst‐Dependent Stereospecific [3,3]‐Sigmatropic Rearrangement of Sulfoxide‐Ynamides: Divergent Synthesis of Chiral Medium‐Sized N,S‐Heterocycles DOI
Guang‐Yu Zhu,

Ji‐Jia Zhou,

Li‐Gao Liu

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(28)

Published: April 27, 2022

Medium-sized N,S-heterocycles have received tremendous interest due to their biological activities and potential medical applications. However, asymmetric synthesis of these compounds are extremely rare. Described herein is a catalyst-dependent [3,3]-sigmatropic rearrangement sulfoxide-ynamides, enabling divergent atom-economic series valuable medium-sized in moderate good yields with broad substrate scope. Importantly, excellent enantioselectivities been achieved via an unprecedented chirality-transfer. Moreover, theoretical calculations employed elucidate the origins stereospecific [3,3]-rearrangement.

Language: Английский

Citations

40
Copper‐Catalyzed Enantioselective Doyle–Kirmse Reaction of Azide‐Ynamides via α‐Imino Copper Carbenes DOI
Xin Liu, Li‐Gao Liu,

Can‐Ming Chen

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(10)

Published: Jan. 14, 2023

[2,3]-Sigmatropic rearrangement reaction involving sulfonium ylide (Doyle-Kirmse reaction) generated from metal carbenes represents one of the powerful methods for construction C(sp3 )-S and C-C bonds. Although significant advances have been achieved, asymmetric versions via generation ylides rarely reported to date, they so far limited diazo compounds as carbene precursors. Here, we describe a copper-catalyzed enantioselective Doyle-Kirmse azide-ynamide cyclization, leading practical divergent assembly an array chiral [1,4]thiazino[3,2-b]indoles bearing quaternary carbon stereocenter in generally moderate excellent yields enantioselectivities. Importantly, this protocol unique catalytic non-diazo approach unprecedented [2,3]-sigmatropic α-imino carbenes.

Language: Английский

Citations

30
Chiral Brønsted acid-catalyzed asymmetric intermolecular [4 + 2] annulation of ynamides with para-quinone methides DOI

Hang‐Hao Li,

Ya-Nan Meng,

Can‐Ming Chen

et al.

Science China Chemistry, Journal Year: 2023, Volume and Issue: 66(5), P. 1467 - 1473

Published: April 12, 2023

Language: Английский

Citations

18
Brønsted acid–catalyzed asymmetric dearomatization for synthesis of chiral fused polycyclic enone and indoline scaffolds DOI Creative Commons
Tong‐De Tan,

Gan-Lu Qian,

Hao-Ze Su

et al.

Science Advances, Journal Year: 2023, Volume and Issue: 9(11)

Published: March 15, 2023

In the past two decades, substantial advances have been made on asymmetric alkyne functionalization by activation of inert alkynes. However, these transformations so far mostly limited to transition metal catalysis, and chiral Brønsted acid-catalyzed examples are rarely explored. Here, we report a dearomatization reaction phenol- indole-tethered homopropargyl amines, allowing practical atom-economical synthesis diverse array valuable fused polycyclic enones indolines bearing quaternary carbon stereocenter contiguous stereogenic centers in moderate good yields with excellent diastereoselectivities generally enantioselectivities (up >99% enantiomeric excess). This protocol demonstrates dearomatizations via vinylidene-quinone methides.

Language: Английский

Citations

16
Copper-catalyzed enantioselective diyne cyclizationviaC(sp2)–O bond cleavage DOI Creative Commons

Ji‐Jia Zhou,

Ya-Nan Meng,

Li‐Gao Liu

et al.

Chemical Science, Journal Year: 2023, Volume and Issue: 14(13), P. 3493 - 3500

Published: Jan. 1, 2023

A copper-catalyzed asymmetric cascade cyclization via C(sp 2 )–O bond cleavage is disclosed, affording a range of chromeno[3,4- c ]pyrroles bearing triaryl oxa-quaternary carbon stereocenter in high yields and enantioselectivities.

Language: Английский

Citations

14
Borane-catalyzed cascade Friedel–Crafts alkylation/[1,5]-hydride transfer/Mannich cyclization to afford tetrahydroquinolines DOI Creative Commons
Beibei Zhang,

Shuo Peng,

Feiyi Wang

et al.

Chemical Science, Journal Year: 2021, Volume and Issue: 13(3), P. 775 - 780

Published: Dec. 20, 2021

An unprecedented redox-neutral annulation reaction of tertiary anilines with electron-deficient alkynes was developed that proceeds through a cascade Friedel-Crafts alkylation/[1,5]-hydride transfer/Mannich cyclization sequence. Under B(C6F5)3 catalysis, range functionalized 1,2,3,4-tetrahydroquinolines were facilely constructed in moderate to good yields exclusive 3,4-anti-stereochemistry. The commercial availability the catalyst and high atom step economy procedure, together metal-free external oxidant-free conditions, make this an attractive method organic synthesis.

Language: Английский

Citations

25