Catalytic Enantioselective Petasis-Type Reaction of Quinolines Catalyzed by a Newly Designed Thiourea Catalyst

Yamaoka, Yousuke; Miyabe, Hideto; Takemoto, Yoshiji

doi:10.1021/ja071470x

Cited by 272 publications

(121 citation statements)

References 28 publications

(23 reference statements)

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“…Therefore, for the receptors 8, 9, and 12, we performed a similar analysis to that described already for these receptors. [23] We first noticed that the equation that describes Michael-Menten kinetics in the presence of a competing product, can be further simplified if one assumes that the association constant of the product and the substrate is similar; see Equation (1). (1) Numerical integration of the kinetic equations was performed using the fourth-order Runge-Kutta method.…”

Section: Resultsmentioning

confidence: 99%

“…[23] We first noticed that the equation that describes Michael-Menten kinetics in the presence of a competing product, can be further simplified if one assumes that the association constant of the product and the substrate is similar; see Equation (1). (1) Numerical integration of the kinetic equations was performed using the fourth-order Runge-Kutta method. [40] In this analysis it is assumed that the mechanism is first order in pyrrolidine (n = 1) and that the contribution from a bimolecular mechanism is negligible.…”

Section: Resultsmentioning

confidence: 99%

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Enzyme Mimics for Michael Additions with Novel Proton Transport Groups

et al. 2008

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Molecular receptors with an enzyme‐like behavior in the Michael addition of pyrrolidine to an α,β‐unsaturated lactam have been designed. Catalytic activities are discussed and related to the substrate association constants. Chiral assistance of enantiomerically pure receptors was also investigated. One of the receptors shows a 4:1 enantiomeric ratio (60 % ee) for the addition of pyrrolidine and 3‐pyrroline.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Enzyme Mimics for Michael Additions with Novel Proton Transport Groups

et al. 2008

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“…This tetra-coordinated intermediate was proposed in earlier work. 11,[27][28][29] Since this species was 68.5 kJ•mol -1 in energy above the reactants, its existence could not be observed or detected experimentally.…”

Section: Formation Of Tetra-coordinated Borate Intermediatementioning

confidence: 97%

Theoretical Study on the Mechanism of the Petasis‐type Boronic Mannich Reaction of Organoboronic Acids, Amines, and α‐Hydroxy Aldehydes

Tao¹,

Li²

2010

Chin. J. Chem.

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The mechanism of a typical Petasis-type boronic mannich reaction (the styrylboronic acid, dibenzylamine, and α-hydroxylpropionaldehyde) has been investigated using density functional theory calculations. According to our calculations, the reaction is most likely to proceed through the following steps: 1) the nucleophilic addition of the amine to the aldehyde to form the carbinolamine; 2) the dehydration of the carbinolamine; 3) the formation of the tetra-coordinated borate intermediate; 4) the C-C bond formation by the intramolecular transfer of the styryl group; 5) the hydrolysis of the resulting intermediate to give the final products. The highest point on the energy profile is the transition state for the C-C bond formation (118.8 kJ•mol -1 above the reactants in ethanol). Our results cangive reasonable explanations on some experimental facts observed for many Petasis-type boronic Mannich reactions.

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“…4) in the transformation of quinoline 9a with (E)-styrylboronic acid 10A into 2-alkylated dihydroquinoline (Table 2). 112,113) The addition of phenyl chloroformate (2 eq) as a N-acylating reagent was essential to undergo the reaction in CH 2 Cl 2 at Ϫ65°C. Among the new catalysts prepared, thiourea 8a gave the best results to afford the 1,2-adduct 11aA in 70% yield with 90% ee without formation of 1,4-adduct (entries 1-9).…”

Section: )mentioning

confidence: 99%

Development of Chiral Thiourea Catalysts and Its Application to Asymmetric Catalytic Reactions

Takemoto

2010

CHEMICAL & PHARMACEUTICAL BULLETIN

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395

107

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We have developed several multifunctional thiourea catalysts bearing a tertiary amine or an 1,2-amino alcohol in expectation of their synchronous activation of a nucleophile and an electrophile through both acid-base and hydrogen-bonding interactions. From these studies, it was revealed that the weak acidity of thioureas compared with metallic Lewis acids could be overcome by this modification. The bifunctional aminothiourea could be used efficiently for a wide range of diastereoselective and enantioselective nucleophilic reactions such as Michael addition of 1,3-dicarbonyl compounds to nitroolefines, aza-Henry reaction of nitroalkanes to N-Boc imines, and hydrazination of cyclic b b-keto esters. We also discovered that multifunctional thiourea catalyst, bearing an 1,2-amino alcohol moiety, significantly accelerated the Petasis-type reaction of alkenylboronic acids to Nphenoxycarbonyl quinolinium salts, prepared from quinolines and phenyl chloroformate, to afford 1,2-addition products with high enantioselectivity (up to 97% ee). Furthermore, to expand the synthetic applicability of the thiourea-catalyzed asymmetric reactions, tandem organocatalyzed reactions were explored to establish the concise one-pot synthesis of chiral densely functionalized three-, five-, and six-membered compounds.

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Catalytic Enantioselective Petasis-Type Reaction of Quinolines Catalyzed by a Newly Designed Thiourea Catalyst

Cited by 272 publications

References 28 publications

Enzyme Mimics for Michael Additions with Novel Proton Transport Groups

Enzyme Mimics for Michael Additions with Novel Proton Transport Groups

Theoretical Study on the Mechanism of the Petasis‐type Boronic Mannich Reaction of Organoboronic Acids, Amines, and α‐Hydroxy Aldehydes

Development of Chiral Thiourea Catalysts and Its Application to Asymmetric Catalytic Reactions

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