Ruthenium-Catalyzed Transformation of Aryl and Alkenyl Triflates to Halides
摘要:
Aryl triflates were transformed to aryl bromides/iodides simply by treating them with LiBr/NaI and [Cp*Ru(MeCN)(3)]OTf. The ruthenium complex also catalyzed the transformation of alkenyl sulfonates and phosphates to alkenyl halides under mild conditions. Aryl and alkenyl triflates undergo oxidative addition to a ruthenium(II) complex to form eta(1)-arylruthenium and 1-ruthenacyclopropene intermediates, respectively, which are transformed to the corresponding halides.
Aminocarbonylations of alkenyl phosphates, chlorides, bromides, and triflates with Mo(CO)6 as a solid CO source
作者:Olof Lagerlund、Mette L.H. Mantel、Mats Larhed
DOI:10.1016/j.tet.2009.06.101
日期:2009.9
Palladium-catalyzedaminocarbonylations of alkenyl chlorides, bromides, and triflates were investigated using Mo(CO)6 as a solid carbonmonoxidesource. The reactions afforded moderate to good yields producing a wide variety of acrylamides after 20 min of microwave irradiation. In addition, the aminocarbonylationreaction was, for the first time, expanded to include alkenyl phosphates as starting materials
A catalytic system comprised of Pd(OAc)2 and bidentate ligand dppe enabled first direct arylations with moisture-stable aryl sulfamates as electrophiles, and proved applicable to unprecedented C−H bond functionalizations with easily accessible alkenyl phosphates as well as benzyl phosphates.
The title reaction in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium(0) affords alkylative coupling products in good to excellent yields in 1,2-dichloroethane at room temperature. This coupling reaction under C(sp2)–O cleavage proceeds stereospecifically. The reaction does not affect a coexisting vinyl sulfide group. This feature enables 1,2- and 1,3-carbonyl transposition
Carboncarbon bond formation by cross-coupling of enol phosphates with organoaluminium compounds catalyzed by palladium(O) complex
作者:Kazuhiko Takai、Koichiro Oshima、Hitosi Nozaki
DOI:10.1016/0040-4039(80)80120-1
日期:1980.1
Trialkylaluminium-mediated alkylation of enolphosphates under the CObond cleavage is performed stereospecifically in the presence of a catalytic amount of Pd(PPh3)4. Alkenylation and alkynylation are also described.
The reaction of allylic phosphates with the title organoaluminium reagent (PhMe2Si-AlEt2) provides allylsilanes in good yields. Cross coupling of enol phosphates with PhMe2Si-Mtl (Mtl = AlEt2 or MgMe) produces vinylsilanes regio- and stereoselectively in the presence of Pd(0) catalysts.