Gold‐Catalyzed Dealkoxylative Carbocyclization/[3+3] Annulation Cascade of Acetal–Allene or Ketal–Allene Substrates

Teng, Tse-Min; Lin, Ming‐Shiun; Vasu, Dhananjayan; Bhunia, Sabyasachi; Liu, Ting-An; Liu, Rai‐Shung

doi:10.1002/chem.201000041

Cited by 22 publications

(3 citation statements)

References 61 publications

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“…In this context, we thought that allylsilane derivatives, a particular case of alkyl-substituted alkenes, could be appropriate alkene partners for our desired reaction. [8] Allylsilanes are relatively good nucleophiles and then, addition to iminium species 6 should be easier than the addition of conventional alkenes. Moreover, the silyl group in b-position could stabilize the cationic intermediate 10 favouring the desired reaction (Scheme 1).…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Pyrrolidine Derivatives by a Platinum/Brønsted Acid Relay Catalytic Cascade Reaction

Galván

Calleja

Fañanás

et al. 2014

Chemistry A European J

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A new catalytic reaction for the synthesis of pyrrolidine derivatives is presented. The method implies the coupling of N-Boc-protected alkynamine derivatives and appropriate alkenes or alkynes in a process catalysed by a platinum/triflic acid catalytic binary system. This reaction is believed to proceed through a cascade process implying an initial platinum-catalysed cycloisomerization of the alkynamine derivative followed by a triflic acid promoted nucleophilic addition of the alkene or alkyne and trapping of the cationic species formed by the Boc group. Not only simple alkenes and alkynes were used in this reaction but also allyltrimethylsilane and propargyltrimethylsilane. Particularly, when allyltrimethylsilane is used as the alkene counterpart interesting bicyclic compounds containing a trimethylsilane group are obtained. However, when propargyltrimethylsilane is used in the presence of water we observed the formation of a related bicyclic compound lacking the trimethylsilane group and containing an exocyclic carbon-carbon bond.

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Section: Resultsmentioning

confidence: 99%

Synthesis of Pyrrolidine Derivatives by a Platinum/Brønsted Acid Relay Catalytic Cascade Reaction

Galván

Calleja

Fañanás

et al. 2014

Chemistry A European J

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“…We first tested the intramolecular cyclizations of allenyl acetal 1a with PPh 3 AuCl/AgSbF 6 (5 mol %), which was shown to be an active catalyst in the two cascade reactions, as depicted in Scheme 1 [17–18]. As shown in Table 1, the treatment of compound 1a with this gold catalyst (5 mol %) in dichloromethane (DCM, 28 °C, 0.5 h) afforded 5-isopropylidenecyclopent-2-en-1-one derivative 4a in 65% yield (Table 1, entry 1).…”

Section: Resultsmentioning

confidence: 99%

“…In this cascade sequence, two new rings and three chemical bonds are generated in a one-pot procedure. We previously reported gold-catalyzed reactions of allenyl acetals with suitable dipolarophiles such as 1,3-diones to chemoselectively produce the cycloaddition product 2 [17] (Scheme 1). Similar reactions with nitrones stereoselectively delivered distinct formal cycloadducts 3 [18].…”

Section: Introductionmentioning

confidence: 99%

Gold-catalyzed cyclization of allenyl acetal derivatives

Vasu¹,

Pawar²,

Liu³

2013

Beilstein J. Org. Chem.

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SummaryThe gold-catalyzed transformation of allenyl acetals into 5-alkylidenecyclopent-2-en-1-ones is described. The outcome of our deuterium labeling experiments supports a 1,4-hydride shift of the resulting allyl cationic intermediates because a complete deuterium transfer is observed. We tested the reaction on various acetal substrates bearing a propargyl acetate, giving 4-methoxy-5-alkylidenecyclopent-2-en-1-ones 4 via a degradation of the acetate group at the allyl cation intermediate.

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The Chemistry of Gold–Allene Complexes

Muñoz

Hurtado-Rodrigo

2014

Patai's Chemistry of Functional Groups

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In recent years, gold‐electrophilic activation of allenes has unraveled a huge potential for new reactivities toward the synthesis of complex molecules with synthetic or biological importance. Gold and allenes are a unique combination that has shown to be very versatile and give better reactivity, and in some cases is complementary to other metals. Coordination of gold to allenes is more complex than coordination to a simple olefin or alkyne, and several types of structures can be predicted depending on the atoms involved in the coordination. The nature of the gold–allene interaction defines the reactivity of these complexes, which can be modulated toward the desired product by slight changes in the catalysts or reaction conditions. New reactions involving gold–allene complexes for the formation of carbon–heteroatom or carbon–carbon bond formation will be discussed in this chapter, including inter‐ and intramolecular examples of nucleophilic additions, and inter‐ and intramolecular cycloaddition and cycloisomerization reactions with alkenes, dienes, alkynes, and other allenes.

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Gold‐Catalyzed Dealkoxylative Carbocyclization/[3+3] Annulation Cascade of Acetal–Allene or Ketal–Allene Substrates

Cited by 22 publications

References 61 publications

Synthesis of Pyrrolidine Derivatives by a Platinum/Brønsted Acid Relay Catalytic Cascade Reaction

Synthesis of Pyrrolidine Derivatives by a Platinum/Brønsted Acid Relay Catalytic Cascade Reaction

Gold-catalyzed cyclization of allenyl acetal derivatives

The Chemistry of Gold–Allene Complexes

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