Regio‐ and Enantioselective (3+3) Cycloaddition of Nitrones with 2‐Indolylmethanols Enabled by Cooperative Organocatalysis

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(5), P. 2355 - 2363

Published: Oct. 22, 2020

Abstract The regio‐ and enantioselective (3+3) cycloaddition of nitrones with 2‐indolylmethanols was accomplished by the cooperative catalysis hexafluoroisopropanol (HFIP) chiral phosphoric acid (CPA). Using this approach, a series indole‐fused six‐membered heterocycles were synthesized in high yields (up to 98 %), excellent enantioselectivities 96 % ee ) exclusive regiospecificity. This approach enabled not only first organocatalytic asymmetric but also C3‐nucleophilic 2‐indolylmethanols. More importantly, theoretical calculations elucidated role cocatalyst HFIP helping CPA control reactivity enantioselectivity reaction, demonstrating new mode catalysis.

Language: Английский

---

Cooperative Catalysis for the Highly Diastereo‐ and Enantioselective [4+3]‐Cycloannulation of ortho‐Quinone Methides and Carbonyl Ylides

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(14), P. 5536 - 5540

Published: Jan. 2, 2020

We describe herein a highly diastereo- and enantioselective [4+3]-cycloannulation of ortho-quinone methides carbonyl ylides to furnish functionalized oxa-bridged dibenzooxacines with excellent yields stereoselectivity in single synthetic step. The combination rhodium chiral phosphoric acid catalysis working concert generate both transient intermediates situ provides direct access complex bicyclic products two quaternary one tertiary stereogenic centers. may be further into valuable enantiomerically enriched building blocks.

Language: Английский

---

Advances in organocatalytic asymmetric reactions of vinylindoles: powerful access to enantioenriched indole derivatives

Organic Chemistry Frontiers, Journal Year: 2021, Volume and Issue: 8(11), P. 2643 - 2672

Published: Jan. 1, 2021

This review summarizes advances in vinylindole-based organocatalytic asymmetric reactions since 2008 and includes the applications of some methodologies total synthesis natural products, points out remaining challenges this research area.

Language: Английский

---

Organocatalytic Enantioconvergent Synthesis of Tetrasubstituted Allenes via Asymmetric 1,8-Addition to aza-para-Quinone Methides

Organic Letters, Journal Year: 2019, Volume and Issue: 21(19), P. 8127 - 8131

Published: Sept. 23, 2019

In contrast to the well-explored quinone methides (QMs) and aza-ortho-QMs, aza-para-QMs have been rarely studied in terms of their asymmetric transformations. Herein, a highly efficient enantioconvergent 1,8-addition is described. Featuring remarkable remote stereocontrol, this reaction provides expedient access chiral tetrasubstituted allenes bearing an adjacent all-carbon quaternary stereocenter with high enantioselectivity diastereoselectivity.

Language: Английский

---

Atroposelective Construction of Axially Chiral Alkene‐Indole Scaffolds via Catalytic Enantioselective Addition Reaction of 3‐Alkynyl‐2‐indolylmethanols^†

Chinese Journal of Chemistry, Journal Year: 2021, Volume and Issue: 39(8), P. 2163 - 2171

Published: April 29, 2021

Main observation and conclusion Atroposelective construction of axially chiral alkene‐heteroaryl scaffolds is highly desired but challenging. In this work, we established an atroposelective alkene‐indole via the strategy catalytic enantioselective addition reaction 3‐alkynyl‐2‐indolylmethanols with bulky nucleophiles. strategy, α‐amido sulfones were used as competent nucleophiles phosphoric acid (CPA) acted suitable catalyst for reaction. By a new class acyclic alkene‐indoles was synthesized in overall high yields (up to 86%), excellent ( E / Z )‐selectivity (all > 95 : 5) good enantioselectivities 92 8 er). This represents first frameworks, which will add member family atropoisomeric heterocycles, especially indole compounds.

Language: Английский

---

Atroposelective Synthesis of 3,3’‐Bisindoles Bearing Axial and Central Chirality: Using Isatin‐Derived Imines as Electrophiles

Chinese Journal of Chemistry, Journal Year: 2020, Volume and Issue: 38(6), P. 583 - 589

Published: Feb. 27, 2020

Summary of main observation and conclusion An atroposelective synthesis a new class 3,3’‐bisindoles bearing axial central chirality has been established via catalytic asymmetric addition reactions using isatin‐derived imines as electrophiles (23 examples, up to 80% yield, > 95 : 5 dr, 98 2 er). This approach takes advantage chiral phosphoric acid‐catalyzed dynamic kinetic resolution 2‐substituted nucleophilic such substrates with imines. In this approach, acted competent due their high reactivity bulky size, which provided an easy access axially 3,3'‐bisindoles incorporated biologically important 3‐aminooxindole unit. greatly expanded the generality applicability strategy for enantioenriched 3,3’‐bisindole derivatives both chirality.

Language: Английский

---

Advances in Catalytic Asymmetric Reactions Using 2-Indolylmethanols as Platform Molecules

Chinese Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 42(10), P. 3351 - 3351

Published: Jan. 1, 2022

Indole-based chiral heterocycles constitute a class of important heterocyclic compounds that are found in numerous natural products, pharmaceuticals, pesticide, and functional materials.The efficient highly enantioselective synthesis indole derivatives has become one the most issues organic chemistry.Due to simple reactivity traditional indoles, their involved catalytic asymmetric reactions very limited, resulting limited types constructed indole-based frameworks.To solve these challenging issues, chemists devised strategy introducing groups ring, so as obtain series functionalized derivatives, namely platform molecules, building blocks for constructing indole-related frameworks.Among them, 2-indolylmethanols which were designed on consideration introduction hydroxymethyl group C2-position ring would change reactive site ring.This molecules can act either electrophiles or nucleophiles, multi-carbon reactions.Therefore, design development have provided new derivatives.The advances using summarized, will open window designing application molecules.

Language: Английский

---

Rational Design of Axially Chiral Styrene‐Based Organocatalysts and Their Application in Catalytic Asymmetric (2+4) Cyclizations

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

Published: Nov. 30, 2021

A new class of axially chiral styrene-based thiourea tertiary amine catalysts, which have unique characteristics such as an efficient synthetic route, multiple elements, and activating groups, has been rationally designed. These catalysts proven to be organocatalysts, enabling the chemo-, diastereo-, enantioselective (2+4) cyclization 2-benzothiazolimines with homophthalic anhydrides in good yields (up 96 %) excellent stereoselectivities (all >95:5 dr, up 98 % ee). More importantly, theoretical calculations elucidated important role styrene moiety controlling both reactivity enantioselectivity. This work not only represents first design catalytic asymmetric 2-benzothiazolimines, but also gives in-depth understanding organocatalysts.

Language: Английский

---

Construction of Oxygen‐ and Nitrogen‐based Heterocycles from p‐Quinone Methides

The Chemical Record, Journal Year: 2021, Volume and Issue: 21(12), P. 4150 - 4173

Published: Aug. 9, 2021

In the last few years, there has been an explosive growth in area of para-quinone methide (p-QM) chemistry. This boom is actually due to unique reactivity pattern p-QMs, and also their remarkable synthetic applications. fact, p-QMs serve as synthons for unsymmetrical diaryl- triarylmethanes, construction diverse range carbocycles heterocycles. a wide structurally complex heterocyclic frameworks could be accessed through transformations modified stable p-QMs. Therefore, main focus this review article cover recent advancements transition-metal, Lewis acid base-catalyzed/mediated p-quinone methides (p-QMs) oxygen- nitrogen-containing

Language: Английский

---

Organocatalytic enantioselective dearomatization of thiophenes by 1,10-conjugate addition of indole imine methides

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Aug. 12, 2021

Abstract Catalytic asymmetric dearomatization (CADA) is a powerful tool for the rapid construction of diverse chiral cyclic molecules from cheap and easily available arenes. This work reports an organocatalytic enantioselective substituted thiophenes in context rare remote 1,10-conjugate addition. By suitable stabilization thiophenyl carbocation with indole motif form imine methide, excellent chemo-, regio-, stereocontrol nucleophilic addition can be achieved phosphoric acid catalysis under mild conditions. protocol successfully extended to other heteroarenes including selenophenes furans. Control experiments DFT calculations demonstrate possible pathway which hydrogen bonding plays important role selectivity control.

Language: Английский

---