Consecutive Intramolecular Hydroamination/Asymmetric Transfer Hydrogenation under Relay Catalysis of an Achiral Gold Complex/Chiral Brønsted Acid Binary System

Han, Zhi‐Yong; Xiao, Han; Chen, Xiao-Hua; Gong, Liu‐Zhu

doi:10.1021/ja903547q

Cited by 364 publications

(130 citation statements)

References 43 publications

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“…Recently, Gong et al reported that an achiral Au complex compatibly worked with a chiral phosphoric acid to promote a tandem hydroamination/reduction reaction, [30] readily transforming 2-(2-propynyl)aniline derivatives 124 into tetrahydroquinolines 126 in one operation with excellent ee (see Scheme 23). This cascade was initiated by a Au-catalyzed intermolecular hydroamination of alkynes 124, fol- lowed by a Brønsted acid catalyzed enantioselective transfer hydrogenation using Huntzsch ester.…”

Section: By the Combination Of Metal And Organocatalystsmentioning

confidence: 99%

Recent Advances in Multicatalyst Promoted Asymmetric Tandem Reactions

Zhou

2010

Chemistry An Asian Journal

440

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Dedicated to the 150th anniversary of Japan-UK diplomatic relations FOCUS REVIEWSAbstract: Multicatalyst promoted asymmetric tandem reactions have emerged as a powerful strategy to improve the synthetic efficiency. It enables the synthesis of complex molecules with high selectivity from simple starting materials in an almost biomimetic-like way. The use of multiple catalyst systems can enlarge the substrate and reaction scope for the reaction design, improve the reactivity, and benefit the control of selectivity. In this FocusReview, the current achievement of this promising field is discussed, including the advantages and difficulties of this research, and the strategies applied to address these problems.

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Section: By the Combination Of Metal And Organocatalystsmentioning

confidence: 99%

Recent Advances in Multicatalyst Promoted Asymmetric Tandem Reactions

Zhou

2010

Chemistry An Asian Journal

440

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“…Scheme 28. Positive results were also obtained for intramolecular hydroaminations using combinations of (Ph 3 P)AuMe and phosphoric acid diesters HOP(O)-(OR) 2 . With the two OR groups fused together in a chiral ester, such as in biphen-diyl-or binaphth-diyl-2,2 -dioxo esters, the process can be conducted with high enantioselectivity [83]. In the present context it is of interest that the corresponding catalyst solutions prepared from (Ph 3 P)AuCl and the silver salt of some acid esters gave much poorer yields.…”

Section: The Acid Route Using Organogold(i) Complexes [(L)aur]mentioning

confidence: 95%

Silver-free Gold(I) Catalysts for Organic Transformations

Schmidbaur

Schier

2011

Zeitschrift Für Naturforschung B

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The majority of gold(I) catalysts employed in organic transformations in homogeneous systems are presently generated in situ by reactions of gold halides AuX or their 1 : 1 complexes [(L)AuX] with silver salts AgY (X = Cl, Br; L = R 3 P, NHC, tht etc.; Y = BF 4 , PF 6 , SbF 6 , OSO 2 CF 3 , OC(O)CF 3 etc.). This usage of silver salts is not only economically unfavorable, but also has several practical disadvantages regarding inter alia the thermal and photochemical stability of the reaction mixtures, problems of inexact stoichiometries, difficulties in separation and recycling, and cooperative effects due to Au-Ag metallophilic interactions which can induce a different course of the reactions. There is therefore a move towards syntheses of silver-free homogeneous gold(I) catalysts. The past and current approaches and opportunities are summarized in this review.

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“…[41] Gong reported that the gold catalysis and Brønsted acid catalysis are compatible in the gold-catalyzed hydroamination and transfer hydrogenation. [42] However, those works refer to dual or cooperative catalysis. Furthermore, some asymmetric gold-catalyzed cyclizations are known, using either chiral ligands or chiral anions, [43] but to the best of our knowledge, there is no example in the literature in which Single-crystal X-ray structure analysis of 50.…”

Section: Nitroenynesmentioning

confidence: 99%

“…(3R,4R,5S,Z)-2-Benzylidene-5-ethoxy-4-isopropyl-3-(nitromethyl)tetrahydrofuran (42) From (E)-(4-nitrobut-3-en-1-ynyl)benzene 5a, isovaleraldehyde 1a and ethanol according to General Procedure 6 to give a mixture of diastereoisomers (trans/cis: 92/8) as a yellow oil. The crude product was purified by flash column chromatography on silica gel (AcOEt/cyclohexane: 10/90) to provide a yellow oil; yield: 56 mg (80%).…”

Section: X-ray Analysismentioning

confidence: 99%

Organocatalyzed Conjugate Addition of Carbonyl Compounds to Nitrodienes/Nitroenynes and Synthetic Applications

et al. 2010

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The purpose of this study is to point out the synthetic utility of a new class of Michael acceptors (nitrodienes and nitroenynes). The highly enantioselective organocatalytic Michael addition of carbonyl compounds to these functionalized nitroolefins has been carried out in the presence of (S)-diphenylprolinol silyl ether to achieve some interesting building blocks in high selectivities. The adducts thus obtained can be easily converted by taking advantage of the corresponding unsaturated carbon-carbon bond. In presence of the double bond, metathesis or electrophilic activation could be carried out whereas in the presence of the triple bond electrophilic activation could be conducted. We thus focused on a gold-catalyzed cyclization of the bis-homopropargylic alcohol to afford the corresponding substituted tetrahydrofuran. Then, we also demonstrated that organic and gold catalysts were compatible in a one-pot process. Indeed, we developed a one-pot enantioselective organocatalytic Michael addition to a nitroenyne followed by a gold-catalyzed acetalization/cyclization to achieve tetrahydrofuranyl ethers in high diastereoand enantioselectivities with excellent yields.

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Consecutive Intramolecular Hydroamination/Asymmetric Transfer Hydrogenation under Relay Catalysis of an Achiral Gold Complex/Chiral Brønsted Acid Binary System

Abstract: Consecutive hydroamination/asymmetric transfer hydrogenation under relay catalysis of an achiral gold complex/chiral Brønsted acid binary system has been described for the direct transformation of 2-(2-propynyl)aniline derivatives into tetrahydroquinolines with high enantiomeric purity.

Cited by 364 publications

References 43 publications

Recent Advances in Multicatalyst Promoted Asymmetric Tandem Reactions

Recent Advances in Multicatalyst Promoted Asymmetric Tandem Reactions

Silver-free Gold(I) Catalysts for Organic Transformations

Organocatalyzed Conjugate Addition of Carbonyl Compounds to Nitrodienes/Nitroenynes and Synthetic Applications

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