A solvent-dependent chirality-switchable thia-Michael addition to α,β-unsaturated carboxylic acids using a chiral multifunctional thiourea catalyst

Interactions between solvents and solutes are a cornerstone of physical organic chemistry and have been the subject of investigations over the last century. In recent years, a renewed interest in fundamental aspects of solute–solvent interactions has been sparked in the field of supramolecular chemistry in general and that of supramolecular polymers in particular. Although solvent effects in supramolecular chemistry have been recognized for a long time, the unique opportunities that supramolecular polymers offer to gain insight into solute–solvent interactions have become clear relatively recently. The multiple interactions that hold the supramolecular polymeric structure together are similar in strength to those between solute and solvent. The cooperativity found in ordered supramolecular polymers leads to the possibility of amplifying these solute–solvent effects and will shed light on extremely subtle solvation phenomena. As a result, many exciting effects of solute–solvent interactions in modern physical organic chemistry can be studied using supramolecular polymers. Our aim is to put the recent progress into a historical context and provide avenues toward a more comprehensive understanding of solvents in multicomponent supramolecular systems.

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“…20 Yet, solvent effects on chemical reactivity and selectivity remain an active area of research up to this day. 21 …”

Section: The Role Of Solvents In Covalent Chemistrymentioning

confidence: 99%

“…Many of these effects have been studied thoroughly halfway through the previous century , and have become textbook knowledge . Yet, solvent effects on chemical reactivity and selectivity remain an active area of research up to this day …”

Section: The Role Of Solvents In Covalent Chemistrymentioning

confidence: 99%

Solute–Solvent Interactions in Modern Physical Organic Chemistry: Supramolecular Polymers as a Muse

2020

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“…The developed integrated catalyst ( 115 or 126 ) was further applied to a thia‐Michael addition to α,β‐unsaturated carboxylic acids (Scheme 28). [50] Electron‐rich thiophenol derivatives were introduced to various carboxylic acids with high enantioselectivities under similar reaction conditions as the aza‐Michael reactions ( 129 – 131 ). A unique feature of the thia‐Michael reaction is a solvent‐dependent chirality switch: the chirality of the products could be inverted just by changing the solvent without using the antipode of the catalyst.…”

Section: Reactions Of Carboxylic Acidsmentioning

confidence: 99%

“…the carboxylic acid is a potential side reaction, the desired reductive CÀ N bond formation proceeded preferentially. Both aliphatic amines (47) and aromatic amines (48)(49)(50) were suitable substrates for the N-methylation using formic acid. In addition, a variety of functional groups were compatible, including a nitro group (48), a cyano group (49), and an ester group (50).…”

Section: Reductionmentioning

confidence: 99%

Boron Catalysis in the Transformation of Carboxylic Acids and Carboxylic Acid Derivatives

Sawamura

Shimizu

2022

Eur J Org Chem

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Carboxylic acids, amides, and esters are ubiquitous motifs in functional organic molecules. However, the reactivities of these high oxidation state carbonyl compounds are far lower than ketones and aldehydes, and catalysts applicable to transform this class of carbonyl compounds are limited. On the other hand, boron catalysts have found various applications in the transformation of carbonyl compounds by taking advantage of the unique properties derived from their vacant p-orbitals. The continuous advancement of boron catalysis has realized several unprecedented direct transformations of carboxylic acids, amides, and esters in the past decade. In this review, representative achievements of boron catalysis are summarized according to reaction types by focusing on their applications to non-activated carboxylic acids, amides, and esters.

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“…This catalytic method allows for the concise synthesis of natural and unnatural chiral synthons. 18) 3.3. Developing Asymmetric Thia-Michael Addition Organosulfur compounds, validated as synthesis targets for novel bioactive compounds, exhibit a wide variety of functions in vivo.…”

Section: Design Of the Amino Thiourea-arylboronic Acidmentioning

confidence: 99%

Molecular Transformation Based on an Innovative Catalytic System

Takemoto

2021

CHEMICAL & PHARMACEUTICAL BULLETIN

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Novel innovative catalytic systems such as hydrogen-bond donors and thiourea hybrid catalysts have been developed for the asymmetric synthesis of biologically important pharmaceuticals and natural products. Benzothiadiazines possess a stronger hydrogen-bond donor ability compared to thioureas and exhibit remarkable catalytic performance for the activation of α,β-unsaturated amides. Hybrid thioureas (bearing an arylboronic acid and an ammonium salt) efficiently promote the hetero-Michael addition to α,β-unsaturated carboxylic acids and the O-alkylation of keto enols with 5-chlorofuran-2(5H)-one. These hybrid catalysts enable the first total synthesis of non-racemic avenaol, a noncanonical strigolactone, as well as the asymmetric synthesis of several pharmaceuticals. In addition, this study discovers unique chemical phenomena (i.e., the dual role of benzoic acid as a boron ligand and a proton shuttle, the chirality switch of products by solvent used, and the dynamic kinetic resolution of a racemic electrophile in an S N 2-type reaction).

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A solvent-dependent chirality-switchable thia-Michael addition to α,β-unsaturated carboxylic acids using a chiral multifunctional thiourea catalyst

Abstract: An asymmetric thia-Michael addition of arylthiols to α,β-unsaturated carboxylic acids using a thiourea catalyst that bears arylboronic acid and tertiary amine moieties is reported.

Cited by 22 publications

References 49 publications

Solute–Solvent Interactions in Modern Physical Organic Chemistry: Supramolecular Polymers as a Muse

Solute–Solvent Interactions in Modern Physical Organic Chemistry: Supramolecular Polymers as a Muse

Boron Catalysis in the Transformation of Carboxylic Acids and Carboxylic Acid Derivatives

Molecular Transformation Based on an Innovative Catalytic System

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