Alkynyl halides in ruthenium(II)-catalyzed [2+2] cycloadditions of bicyclic alkenes
Ru-catalyzed [2+2] cycloadditions between bicyclic alkenes and alkynyl halides were found to occur in moderate to good yields. The presence of the halide moiety greatly enhances the reactivity of the alkyne component in the cycloaddition and can be transformed into a variety of products that are difficult or impossible to obtain by direct cycloaddition. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Allen, Anna,Villeneuve, Karine,Cockburn, Neil,Fatila, Elisabeth,Riddell, Nicole,Tam, William
experimental part
p. 4178 - 4192
(2009/05/27)
Rhenium-catalyzed [2 + 2] cycloadditions of norbornenes with internal and terminal acetylenes
Treatment of norbornenes with internal and terminal acetylenes in the presence of a catalytic amount of [ReBr(CO)3(thf)]2 gave cyclobutene derivatives in good to excellent yields. Copyright
Kuninobu, Yoichiro,Yu, Peng,Takai, Kazuhiko
p. 1162 - 1163
(2008/02/12)
Ruthenium-catalyzed [2+2] cycloadditions of alkynyl sulfides and alkynyl sulfones
Ruthenium-catalyzed [2+2] cycloadditions of bicyclic alkenes with alkynyl sulfides and alkynyl sulfones were investigated. The sulfide and sulfone moieties were found to be compatible with the Ru-catalyzed cycloadditions, giving the corresponding cyclobut
Riddell, Nicole,Tam, William
p. 1934 - 1937
(2007/10/03)
Ruthenium-catalyzed [2 + 2] cycloadditions between bicyclic alkenes and alkynyl halides
(Chemical equation presented) Ru-catalyzed [2 + 2] cycloadditions between norbornadiene and alkynyl halides were found to occur in moderate to good yields (32-89%). The presence of the halide moiety greatly enhances the reactivity of the alkyne component in the cycloaddition and can be transformed into a variety of products that are difficult or impossible to obtain via direct cycloaddition.
Villeneuve, Karine,Riddell, Nicole,Jordan, Robert W.,Tsui, Gavin C.,Tam, William
p. 4543 - 4546
(2007/10/03)
REACTIONS OF PHENYL(ARYLSULPHONYL)ACETYLENES WITH OLEFINS AND DIENES
Phenyl(arylsulphonyl)acetylenes 1a and 1b react with olefins and dienes to give the addition products of the two fragments derived from the acetylenic carbon-sulfur bond scission.In the reaction with dienes, the and cycloadducts are also forme
Azzena, Ugo,Cossu, Sergio,Lucchi, Ottorino De,Licini, Giulia,Pasquato, Lucia,Valle, Giovanni
p. 557 - 568
(2007/10/02)
(Z)-AND (E)-1-CHLORO-1,2-BIS(PHENYLSULPHONYL)ETHYLENES: SYNTHONS OF BIS(PHENYLSULPHONYL)ACETYLENE AND OF TERMINAL ACETYLENES IN CYCLOADDITION REACTIONS
The cycloaddition reaction of both isomeric 1-chloro-1,2-bis(phenylsulphonyl)ethylenes 1 leads to the expected Diels-Alder adducts with a number of dienes.The (Z)-isomer is more reactive, but the adducts are dehydrochlorinated with more difficulty and in lower yields than the adducts derived from the cycloaddition of the (E)-isomer.The dehydrochlorinated products are bis(phenylsulphonyl)alkenes which formally derive from the cycloaddition of the hitherto unknown bis(phenylsulphonyl)acetylene.These compounds undergo addition-elimination reaction with Grignard reagents; the products, desulphonylated by sodium amalgam, can be considered as the Diels-Alder adducts of terminal acetylenes.
Cossu, Sergio,Lucchi, Ottorino De
p. 569 - 576
(2007/10/02)
1,2-BIS(PHENYLSULFONYL)ALKENES AS VERSATILE GROUPS IN ORGANIC SYNTHESIS: THE PREPARATION OF ALKYL- AND ARYL-SUBSTITUTED NORBORNADIENES VIA THE DIELS-ALDER CYCLOADDITION - GRIGNARD REACTION - DESULFONYLATION SEQUENCE
A synthetic methodology for the preparation of the formal Diels-Alder cycloadducts of alkyl- and aryl-substituted acetylenes which exemplifies the utility of bis(phenylsulfonyl)alkenes 1 in organic synthesis is presented.The procedure entails -cycloaddition of (e)-1,2-bis(phenylsulfonyl)-1-chloroethylene (4), grignard reaction and desulfonylation; each step occurs in high yield.
Azzena, Ugo,Cossu, Sergio,De Lucchi, Ottorino,Melloni, Giovanni
p. 1845 - 1848
(2007/10/02)
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