Tellurium/lithium exchange reactions in the synthesis of spiroketals and 1,6-dioxygenated systems

Santos, Alcindo A. Dos; Princival, Jefferson L.; Comasseto, J. V.; Barros, S. M.; Neto, José E. Brainer

doi:10.1016/j.tet.2007.03.178

Cited by 22 publications

(10 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In view of this fact, we undertook a systematic investigation on their reactivity and found that b-telluroketones can be converted to the corresponding ketals [16,17] and telluroaldehydes, ketones and esters can be reduced to corresponding hydroxytellurides [18], which were resolved into enantiomers by enzymatic kinetic resolution [19]. All these tellurium containing compounds can be transformed into reactive organometallics, by Te/Li exchange [20], followed by transmetallation [18,21]. The resulting reactive organometallics were employed in the construction of useful carbon frameworks [17] and in the synthesis of insect pheromones [22,23].…”

Section: Resultsmentioning

confidence: 99%

Hydrochalcogenation of activated olefines. Synthesis of functionalized dialkylchalcogenides

Comasseto

Gariani

Princival

et al. 2008

Journal of Organometallic Chemistry

Self Cite

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 99%

Hydrochalcogenation of activated olefines. Synthesis of functionalized dialkylchalcogenides

Comasseto

Gariani

Princival

et al. 2008

Journal of Organometallic Chemistry

Self Cite

View full text Add to dashboard Cite

“…Its enantiomer, lactone (S)-12, was prepared from telluride (S)-10, by the same protocol and used as starting material in the synthesis of the E/Z isomeric mixture of spiroketals 13a and 13b. 35 This synthetic step required the preparation of the di-cerium salt 14, generated by the addition of 2 equiv. of butyllithium to a mixture of the optically active hydroxy telluride (R)-10 and cerium chloride in THF at -78 °C.…”

Section: Application Of the Te / Metal Exchange Reaction In The Synthmentioning

confidence: 99%

“…These compounds are constituents of the flavor of Jamaican rum (Scheme 13). 35 Hydroxy telluride (S)-10 and its racemic mixture were employed as starting materials in the synthesis of the components of the pheromone blend of Mayetiola destructor, Drosophila mulleri and Contarinia pisi. Acetate 15, component of the pheromone blend of C. pisi, was prepared in 80% overall yield from racemic 10 in two steps.…”

Section: Application Of the Te / Metal Exchange Reaction In The Synthmentioning

confidence: 99%

Reactive organometallics from organotellurides: application in organic synthesis

Princival

Santos

Comasseto

2010

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Neste artigo é revisada a preparação de organometálicos reativos a partir de teluretos orgânicos. É comentado o uso dos organometálicos preparados dessa maneira na síntese de substâncias bioativas.In this paper the preparation of reactive organometallics starting from organotellurides is reviewed. The application of the reactive organometallics prepared in this way in the synthesis of bioactive compounds is commented.

show abstract

“…10,11 Our research group has been working in the preparation and application of hydroxy alkyl tellurides in the tellurium/ lithium exchange reaction. 12 These compounds have been efficiently used as alternative organometallic sources of 1,4-dianion intermediates in the synthesis of diols, 13 spiroketals, 14 bioactive butenolides, 15 and in the synthesis of natural products, such as (+/−)-frontalin 16 and (+)-endobrevicomin. 17 In this way, based on the interesting results obtained with the application of oxygen-containing organotellurium compounds [12][13][14][15][16] and following our current interest concerning the development of functionalized alkyl tellurides in organic synthesis, we decided to explore herein…”

Section: Introductionmentioning

confidence: 99%

N-Functionalized organolithium compounds via tellurium/lithium exchange reaction

Vargas

Toledo

Comasseto

2010

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Um conjunto de amino teluretos foram preparados e testados em reações de troca telúrio/ lítio. Os compostos de organolítio contendo nitrogênio foram facilmente preparados utilizando N-Bz teluroaminas e uma combinação de n-butillítio/naftaleto de lítio nas reações de troca. Os correspondentes intermediários dilitiados foram capturados com vários eletrófilos, levando à formação dos respectivos produtos em bons rendimentos. A reação foi empregada na síntese de fenetilaminas.A set of tellurium amines have been evaluated in the tellurium/lithium exchange reaction. The nitrogen-containing organolithium compounds were efficiently prepared by using N-Bz tellurium amines and a mixture of n-butyllithium and lithium naphthalenide (LiNp) for performing the exchange reaction. The corresponding dianion intermediates were trapped with a wide range of electrophiles, furnishing the corresponding products in good to excellent yields. The reaction was also employed in the synthesis of phenethylamines.Keywords: tellurium/lithium exchange reaction, functionalized organolithium, dianion intermediate, phenethylamines IntroductionOrganolithium compounds are versatile and useful organometallics due to their excellent nucleophilic reactivity and importance in synthetic organic chemistry. 1 Among them, functionalized organolithium compounds represent an important class of intermediates with the ability of transfering the functionality to an electrophilic reagent. In this way, the preparation of functionalized organolithium compounds via halogen/lithium 2 and tin/ lithium 3 exchange reactions represent an interesting protocol of carbon-carbon bond formation for the synthesis of polyfunctionalized molecules, as well as a wide range of natural products. For years, several groups have been interested in the study and preparation of different α-, β-, γ-, δ-oxygen or nitrogen-functionalized organolithium intermediates and their reaction with electrophiles. 4,5 However, among these intermediates, the corresponding β-functionalized compounds, showed to be very unstable species, decomposing via β-elimination to give olefins. 6 On the other hand, organotellurium chemistry is a very broad and exciting field with many opportunities for research and development of applications in organic synthesis.7 Many different classes of organotellurium compounds have been prepared to date and successfully employed in different synthetic applications, 8 as well as in the total synthesis of natural products. 9 Among the several applications of organotellurium compounds, the formation of organolithium compounds via tellurium/ lithium exchange reaction represents an interesting protocol with a number of advantages over alternative methods. 10,11 Our research group has been working in the preparation and application of hydroxy alkyl tellurides in the tellurium/ lithium exchange reaction. 12 These compounds have been efficiently used as alternative organometallic sources of 1,4-dianion intermediates in the synthesis of diols, 13 spiroketals, 14 bioactive butenolides, 1...

show abstract

Tellurium/lithium exchange reactions in the synthesis of spiroketals and 1,6-dioxygenated systems

Cited by 22 publications

References 18 publications

Hydrochalcogenation of activated olefines. Synthesis of functionalized dialkylchalcogenides

Hydrochalcogenation of activated olefines. Synthesis of functionalized dialkylchalcogenides

Reactive organometallics from organotellurides: application in organic synthesis

N-Functionalized organolithium compounds via tellurium/lithium exchange reaction

Contact Info

Product

Resources

About