Challenging Task of Ni-Catalyzed Highly Regio-/Enantioselective Semihydrogenation of Racemic Tetrasubstituted Allenes via a Kinetic Resolution Process

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(11), P. 7419 - 7430

Published: March 6, 2024

The first earth-abundant transition metal Ni-catalyzed highly regio- and enantioselective semihydrogenation of racemic tetrasubstituted allenes via a kinetic resolution process as challenging task was well established. This protocol furnishes expedient access to diversity structurally important enantioenriched chiral allylic molecules with high regio-, enantio-, Z/E-selectivity. Remarkably, this proceeded one carbon–carbon double bond allenes, which regioselective complementary the Rh-catalyzed asymmetric version. Deuterium labeling experiments density functional theory (DFT) calculations were carried out reveal reasonable reaction mechanism explain regio-/stereoselectivity.

Language: Английский

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Design and Organocatalytic Asymmetric Synthesis of Indolyl-Pyrroloindoles Bearing Both Axial and Central Chirality

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 88(12), P. 7684 - 7702

Published: Nov. 23, 2022

An axially chiral indolyl-pyrroloindole scaffold, a new member of indole-based scaffolds, has been designed, and the catalytic asymmetric construction this scaffold established by strategy organocatalytic (2 + 3) cycloaddition 3,3'-bisindoles with isoindolinone-based propargylic alcohols. By approach, series derivatives bearing both axial chirality central were synthesized in high yields excellent diastereo- enantioselectivities (up to 95% yield, 91:9 dr, 99% ee). This reaction not only realizes first n) as 1,2-dinucleophiles but also provides for atroposelective scaffolds five-five-membered rings, thus solving challenges constructing class scaffolds.

Language: Английский

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Organocatalytic Enantioselective 1,8-Addition for the Synthesis of Chiral Tetraarylmethanes from 2-Naphthol/Naphthalen-2-amine-Based Tertiary Alcohols

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(26), P. 14562 - 14569

Published: June 21, 2023

Catalytic enantioselective construction of optically active tetraarylmethanes remains a challenging issue in the field asymmetric synthesis because overwhelming steric hindrance and formidable stereocontrol that existed all-aryl-substituted quaternary carbon stereocenter. Here, we reported an organocatalytic chiral from racemic tertiary alcohols. With aid phosphoric acid catalyst, 6-methylenenaphthalen-2(6H)-ones were generated situ 6-(hydroxydiarylmethyl)naphthalen-2-ols, followed by stereoselective 1,8-conjugate addition to afford corresponding high excellent yields with enantioselectivities. Furthermore, scope alcohols has been successfully enlarged 6-(hydroxydiphenylmethyl)naphthalen-2-amines. Notably, it is first time use 2-naphthol/naphthalen-2-amine unit as auxiliary group generate α,β,γ,δ,ε,ζ-conjugate systems, which have involved remote stereocontrolled reactions. Particularly, stereoconvergent formal nucleophilic substitution reaction triarylmethanols achieved for tetraarylmethanes. In addition, DFT calculations applied provide guidance design additional understand origin stereoselectivity.

Language: Английский

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A Bulky Imidodiphosphorimidate Brønsted Acid Enables Highly Enantioselective Prins-semipinacol Rearrangements

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(11), P. 8518 - 8527

Published: May 17, 2024

The development of BINOL-derived Brønsted acid catalysts has been profoundly guided by rational design, with carefully implemented structural changes leading to generations enhanced reaction capabilities. This approach catalyst optimization promoted the integration knowledge gathered in optimizing prior eras acids, and ultimately, molecular features that have contributed success previous designs are preserved. Of these, large substituents at 3 3′ positions BINOL backbone most critical almost every developed structure possessing this feature. However, imidodiphosphorimidate (IDPi) not synthetically well-suited contain same sterically bulky groups associated high selectivity imparted previously structures. Herein, we leveraged moderate size 9-phenanthryl substituent synthesize an IDPi sizable steric demands. applicability was evaluated construction stereochemically dense spirocycles generated via asymmetric Prins-semipinacol sequence. Transition state calculations were deployed interrogate origins enantioselectivity, these demonstrate mechanistic hallmarks can be generalized a genuinely different class catalyst. Ultimately, work provides basis for general design principles translation "privileged" across

Language: Английский

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Catalyst-Controlled Divergent Reactions of 2,3-Disubstituted Indoles with Propargylic Alcohols: Synthesis of 3H-Benzo[b]azepines and Axially Chiral Tetrasubstituted Allenes

Organic Letters, Journal Year: 2022, Volume and Issue: 24(35), P. 6472 - 6476

Published: Aug. 30, 2022

Catalyst-controlled divergent reactions of 2,3-disubstituted indoles with propargylic alcohols were developed for the first time. In presence TsOH or B(C6F5)3 as catalyst, reacted smoothly 3-alkynyl-3-hydroxyisoindolinones to afford 3H-benzo[b]azepines by selective C2(sp2)-C3(sp2) ring expansion indoles. contrast, decreasing catalyst strength (e.g., chiral phosphoric acid) interrupted cascade reactions, affording axially tetrasubstituted allenes bearing an adjacent quaternary carbon stereocenter. Control experiments provided insights into reaction mechanism.

Language: Английский

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Asymmetric organocatalytic (3 + 2) annulation of propargylic alcohols with indolylnaphthalenols: synergistic construction of axial and central chirality

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 10(1), P. 30 - 34

Published: Nov. 14, 2022

Organocatalytic enantioselective construction of chiral spiro N , -acetal carbon stereocenters and axially 3-arylindoles has been achieved in one pot.

Language: Английский

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Organocatalytic enantioselective reaction of tertiary α-(7-indolyl)methanols with tryptamines

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(14), P. 3662 - 3668

Published: Jan. 1, 2023

With the aid of chiral phosphoric acid, enantioselective 1,6-addition tryptamines to in situ formed alkynyl 7-methylene-7 H -indoles from tertiary α-(7-indolyl)methanols has been established, furnishing axially tetrasubstituted allenes high yields.

Language: Английский

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Organocatalytic asymmetric cascade bicyclization: access to chiral polycyclic bisindoles from 2-indolylmethanols and propargylic alcohols

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(7), P. 2040 - 2046

Published: Jan. 1, 2024

A chiral phosphoric acid-catalyzed asymmetric bis-cyclization of α-indolyl propargylic alcohols with 2-indolylmethanols was realized.

Language: Английский

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Organocatalytic Enantioselective 1,12‐Addition of Alkynyl Biphenyl Quinone Methides Formed In Situ

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(29)

Published: May 3, 2024

The chemistry of quinone methides formed in situ has been flourishing recent years. In sharp contrast, the development and utilization biphenyl are rare. this study, we achieved a remote stereocontrolled 1,12-conjugate addition for first time. presence suitable chiral phosphoric acid, alkynyl were generated from α-[4-(4-hydroxyphenyl)phenyl]propargyl alcohols, followed by enantioselective with indole-2-carboxylates. strategy enabled alcohols to serve as efficient allenylation reagents, providing practical access broad range axially allenes bearing (1,1'-biphenyl)-4-ol unit, which previously less accessible. Combined control experiments, density functional theory calculations shed light on reaction mechanism, indicating that enantioselectivity originates nucleophilic methides. Notably, not only versatile intermediates was confirmed but also organocatalytic 1,12-addition established.

Language: Английский

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Organocatalytic Remote Stereocontrolled Synthesis of Tetrasubstituted Allenes via Asymmetric 1,8‐Addition of Propargylic Aza‐p‐Quinone Methides

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(5), P. 1078 - 1083

Published: Jan. 17, 2024

Abstract An organocatalytic remote stereocontrolled 1,8‐conjugated addition of in situ formed propargylic aza‐ p ‐QMs from α‐(4‐aminophenyl) alcohols and indole‐2‐carboxylates was developed, affording axially chiral tetrasubstituted allenes 62–99% yield with 52–99% ee. The synthetic strategy not only enriches the chemistry ‐quinone methides, but also provides an alternative tool for preparation allenes.

Language: Английский

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