- Cu(I)-catalyzed, α-selective, allylic alkylation reactions between phosphorothioate esters and organomagnesium reagents
-
Regiocontrol of allylic alkylation reactions involving hard nucleophiles remains a significant challenge and continues to be an active area of research. The lack of general methods in which α-alkylation is favored underscores the need for the development of new processes for achieving this type of selectivity. We report that Cu(I) catalyzes the allylic substitution of phosphorothioate esters with excellent α-regioselectivity, regardless of the nature of the Grignard reagent that is used. To the best of our knowledge, the Cu-catalyzed allylic alkylation of phosphorothioate esters has never been described. We have also developed a simple protocol for inducing high α selectivity starting from secondary allylic halides. This is accomplished by using sodium phosphorothioates as an additive.
- Lauer, Andrew M.,Mahmud, Farzeen,Wu, Jimmy
-
p. 9119 - 9123
(2011/08/04)
-
- An Improved Method for Stereoselective Synthesis of (E)-Alkenes via Alkenyldialkylboranes
-
Successive treatments of alkenyldialkylboranes, formed by the reaction of alkynes and sterically hindered dialkylboranes, with alkyllithium and benzenesulfenyl chloride afforded highly pure (E)-alkenes in good or excellent yields.
- Hoshi, Masayuki,Masuda, Yuzuru,Arase, Akira
-
p. 3985 - 3987
(2007/10/02)
-
- The Reaction of Alkenylboranes with Palladium Acetate. Stereoselective Synthesis of Olefinic Derivatives
-
The reactions of alkenylboranes with palladium acetate were investigated.Alkenyldialkylboranes, derived from terminal alkynes, underwent intramolecular migration reaction in the presence of an equimolar amount of palladium acetate and triethylamine to give (E)-olefins.On the other hand, under the same conditions as above or even in the presence of catalytic amounts of palladium acetate, alkenyldialkylboranes derived from internal alkynes underwent protonolysis reaction to produce (Z)-olefins.An alkenylpalladium intermediate which was presumably involved in the latter reaction was trapped by allylic chloride to give 1,4-dienes.
- Yatagai, Hidetaka
-
p. 1670 - 1676
(2007/10/02)
-