A new tricyclic triketone from tandem condensation reactions

Reingold, I. David; Butterfield, Anna M.; Daglen, Bevin C.; Walters, Robert S.; Allen, Kathryn; Scheuring, Susan; Kratz, K.; Gembický, Milan; Baran, Peter

doi:10.1016/j.tetlet.2005.03.182

Cited by 7 publications

(1 citation statement)

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“…It is also important to note that the tertiary amines 11 or ionic liquids 20 can also act as catalyst for Baylis-Hillman reactions, hence we performed the 3a mediated BaylisHillman reaction without base and the reaction did not work. Since the alkoxy bases can also activate III to produce trace amountof IV, 21 the reaction was carried out in the presence of KO t Bu without catalyst, which resulted the formation of IV in 15% yield. The NHC mediated cyclohexenone dimerization is very rare.…”

Section: Application Of 3-8 Incarbon-carbon Bond Formation Reactionsmentioning

confidence: 99%

(±)Methanodibenzodiazocine tethered [C-H]δ+ functional site: Study towards benzoin condensation and Baylis-Hillman reactions

Sathyanarayana

Prabusankar

2015

J Chem Sci

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New heterocyclic ring systems consisting of (±) methanodibenzodiazocine and imidazolium/ benzimidazolium salts were synthesized in very good yield. Subsequently, these halide salts were subjected to the anion exchange reaction with KPF 6 to yield the corresponding azolium salts in excellent yield. The possible applications of these newly prepared salts were investigated in homogeneous catalysis. Remarkable changes in the catalytic activity were observed by varying the bulkiness of N-substituent at imidazole. Catalytic activity of these newly prepared salts was tested for the benzoin condensation reaction. Exclusive formation of benzoin products were observed in good yield. Similarly, the dimerization of cyclohexen-1-one to Baylis-Hillman type product, 2-(3-oxocyclohexyl)-2-cyclohexen-1-one was studied.

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Section: Application Of 3-8 Incarbon-carbon Bond Formation Reactionsmentioning

confidence: 99%

(±)Methanodibenzodiazocine tethered [C-H]δ+ functional site: Study towards benzoin condensation and Baylis-Hillman reactions

Sathyanarayana

Prabusankar

2015

J Chem Sci

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The Krapcho Dealkoxycarbonylation Reaction of Esters with α‐Electron‐Withdrawing Substituents

Krapcho

Ciganek

2013

Organic Reactions

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The Krapcho reaction involves esters with α‐electron‐withdrawing substituents such as malonates, β‐keto esters, and α‐cyano esters, which undergo dealkoxycarbonylation on being heated in polar aprotic solvents (such as DMSO, DMF, or HMPT) in the presence of water, or in polar aprotic solvents with water in the presence of added salts (such as NaCN, NaCl, LiCl, LiI, or MgCl 2 ). This procedure avoids the use of strongly aqueous acidic and alkaline conditions and tolerates many functional and protecting groups. The chapter presents the mechanistic aspects of this procedure, which include reaction parameters such as solvents, salts, other additives, and the use of microwave irradiation. The diastereoselectivity of protonation of the enolate intermediate leading to the dealkoxycarbonylated products is discussed. Trapping of the intermediate enolate by electrophiles other than a proton is illustrated. Potential side reactions and same‐pot subsequent reactions of substrates are discussed along with functional‐group compatibility for halogens and nitrogen, oxygen, sulfur, selenium, and carbon functional groups. Several examples of applications of this methodology for the synthesis of natural products along with experimental conditions and procedures are presented. Closely related methods are discussed in the Comparison with Other Methods section. The tables, which consist of 371 pages, are grouped according to substrate structure. Selective entries for other methods (excluding classical aqueous acidic or basic methods) are included in the tabular survey for comparative purposes.

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