Asymmetric transformations from sulfoxonium ylides

Chemical Science, Год журнала: 2021, Номер 13(5), С. 1192 - 1209

Опубликована: Дек. 8, 2021

Sulfoxonium ylides are important surrogates for diazo compounds, and their use in industry as safer alternatives has been evaluated during recent years. Beyond the known classical transformations, these have also used a surprising plethora of novel intrinsic chemical reactions, especially Bench stability handling an advantage this class organosulfur molecules. Despite this, efficient asymmetric specifically catalytic enantioselective versions, only recently reported, there specific reasons this. This perspective article covers topic from first studies up to latest advances, giving personal perspectives showing main challenges area coming

Язык: Английский

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Visible-light-induced organocatalytic enantioselective N–H insertion of α-diazoesters enabled by indirect free carbene capture

Chemical Science, Год журнала: 2022, Номер 14(4), С. 843 - 848

Опубликована: Ноя. 29, 2022

While asymmetric insertion of metal carbenes into H-X (X = C, N, O, etc.) bonds has been well-established, control over free is challenging due to the presence strong background reactions and lack any anchor for a catalyst interaction. Here we have achieved first photo-induced metal-free bond this type. With visible light used as promoter chiral phosphoric acid catalyst, α-diazoesters aryl amines underwent smooth N-H form enantioenriched α-aminoesters with high efficiency good enantioselectivity under mild conditions. Key success was use DMSO an additive, which served rapidly capture highly reactive carbene intermediate domesticated sulfoxonium ylide.

Язык: Английский

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Divergent Synthesis of Tetrasubstituted Phenols via [3 + 3] Cycloaddition Reaction of Vinyl Sulfoxonnium Ylides with Cyclopropenones

Organic Letters, Год журнала: 2023, Номер 25(23), С. 4286 - 4291

Опубликована: Июнь 2, 2023

Two categories of tetrasubstituted phenols were prepared via the cycloaddition reaction vinyl sulfoxonnium ylides with cyclopropenones in a switchable manner. Copper carbenoid was proposed as active intermediate process 2,3,4,5-tetrasubstituted formation, while 2,3,5,6-tetrasubstituted generated direct [3 + 3] annulation under metal-free conditions. Further synthetic applications also demonstrated.

Язык: Английский

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Catalytic Enantioselective Nucleophilic α-Chlorination of Ketones with NaCl

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(4), С. 2779 - 2788

Опубликована: Янв. 18, 2024

Catalytic enantioselective α-chlorination of ketones is a highly desirable process. Different from the conventional approaches that employ corrosive electrophilic chlorination reagents, process disclosed here employs nucleophilic chloride, aqueous NaCl solution, and even seawater, as green inexpensive chlorine sources. This mechanistically distinct electronically opposite approach provides facile access to diverse enantioenriched acyclic α-chloro are less straightforward by approaches. With chiral thiourea catalyst, range racemic α-keto sulfonium salts underwent enantioconvergent carbon–chlorine bond formation with high efficiency excellent enantioselectivity under mild conditions. The motif plays crucial triple role permitting smooth dynamic kinetic resolution take place via anion binding mechanism in well-designed phase-transfer system. protocol represents new general platform for asymmetric α-functionalization carbonyl compounds.

Язык: Английский

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Bidirectional Iterative Approach to Sequence-Defined Unsaturated Oligoesters

JACS Au, Год журнала: 2023, Номер 3(1), С. 252 - 260

Опубликована: Янв. 3, 2023

Herein, we describe the development of a new strategy for synthesis unsaturated oligoesters via sequential metal- and reagent-free insertion vinyl sulfoxonium ylides into O-H bond carboxylic acid. Like two directional coupling amino acids (N- to C-terminal C- N-terminal) in peptide synthesis, present approach offers both directions synthesize oligoesters. The addition ylide (acid iteration sequence) one direction (ylide another yield (Z)-configured To perform this iteration, have developed highly regioselective X-H (X = O, N, C, S, halogen) acids, thiols, phenols, amines, indoles, halogen under metal-free reaction conditions. is applied broad range substrates (>50 examples, up 99% yield) eight iterative sequences. Mechanistic studies suggest that rate-limiting step depends on type insertion.

Язык: Английский

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Rhodium(I) Carbene‐Promoted Enantioselective C−H Functionalization of Simple Unprotected Indoles, Pyrroles and Heteroanalogues: New Mechanistic Insights

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(34)

Опубликована: Июнь 17, 2022

A rhodium(I)-diene catalyzed highly enantioselective C(sp2 )-H functionalization of simple unprotected indoles, pyrroles, and their common analogues such as furans, thiophenes, benzofurans with arylvinyldiazoesters has been developed for the first time. This transformation features unusual site-selectivity exclusively at vinyl terminus arylvinylcarbene enables a reliable rapid synthetic protocol to access distinctive class diarylmethine-bearing α,β-unsaturated esters containing one or two heteroarene-attached tertiary carbon stereocenter in high yields excellent enantioselectivities under mild reaction conditions. Mechanistic studies DFT calculations suggest that, compared aniline substrate, more electron-rich indole substrate lowers C-C addition barrier alters rate-determining step reductive elimination, leading different isotope effect.

Язык: Английский

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Synthesis of I(III)/S(VI) reagents and their reactivity in photochemical cycloaddition reactions with unsaturated bonds

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Ноя. 3, 2022

The development of novel methodologies for the introduction sulfoxonium group under mild conditions is appealing but remains underexplored. Herein we report synthesis a class hypervalent iodine reagents with transferrable group. These compounds enable mixed iodonium-sulfoxonium ylide reactivity. well-defined are examined in visible-light-promoted cyclization reactions wide range unsaturated bonds including alkenes, alkynes, nitriles, and allenes. Two distinct pathways identified, which controlled by substituent bond. cycloaddition protocol features simple operation, reaction conditions, excellent functional tolerance, affording broad sulfoxonium-containing cyclic structures moderate to yields. Furthermore, sufoxonium product can be transformed into diverse groups structural motifs via single electron transfer transition-metal catalysis.

Язык: Английский

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Organocatalytic Transformations from Sulfur Ylides

Catalysts, Год журнала: 2023, Номер 13(4), С. 689 - 689

Опубликована: Март 31, 2023

Sulfur ylides are an important class of organic compounds due to their ability perform many different transformations that can give diverse and interesting products with a high degree complexity. Although metal-catalyzed frequent in this compounds, organocatalyzed remain scarce. From initial works, review aims show from sulfur ylides, involving cyclopropanation formal N–H, S–H, C–H insertion reactions, including enantioselective versions. The proposed mechanisms the modes activation these organocatalysts will be covered. Furthermore, advances area potential challenges circumvented near future also discussed.

Язык: Английский

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Cyclic Sulfoxonium Ylides: Synthesis and Chemospecific Reactivity in the Catalytic Alkylation of Indoles

ChemCatChem, Год журнала: 2023, Номер 15(7)

Опубликована: Фев. 7, 2023

Abstract The study of the reactivity cyclic sulfoxonium ylides has been so far neglected, in particular for reactions that forms carbon‐carbon bond at ylide carbon atom. Herein, we describe synthesis by palladium‐catalyzed intramolecular arylation and these C3‐alkylation indoles presence either an acid catalyst or iridium catalyst. This revealed catalysis is only efficient which tether a six‐membered lactone, whereas was better suited to reaction five‐membered ring ketone lactone. observed chemospecificity might be due relative basicity under steric hindrance around carbene intermediate when conducted with

Язык: Английский

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Condition-Dependent Selective Synthesis of Indolo[1,2-c]quinazolines and Indolo[3,2-c]quinolines from 2-(1H-Indol-2-yl)anilines and Sulfoxonium Ylides

The Journal of Organic Chemistry, Год журнала: 2022, Номер 87(15), С. 9815 - 9828

Опубликована: Июль 15, 2022

In this paper, a selective synthesis of indolo[1,2-c]quinazolines and indolo[3,2-c]quinolines through the cascade reactions 2-(1H-indol-2-yl)anilines with sulfoxonium ylides is presented. The formation products involves generation carbene species from ylide its N–H bond insertion reaction 2-(1H-indol-2-yl)aniline followed by deoxygenative imine formation, intramolecular N– or C– nucleophilic addition aromatization. This switchable was condition-dependent. presence K2CO3 in CH3CN, mainly furnished indolo[1,2-c]quinazolines. HOAc dioxane, it selectively afforded indolo[3,2-c]quinolines. addition, direct C–H/N–H functionalization obtained provides convenient access to polycyclic heteroaromatic compounds. These novel protocols have advantages such as readily accessible substrates, easily tunable selectivity, good compatibility diverse functional groups, use air cost-free sustainable oxidant.

Язык: Английский

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