869804-08-0Relevant academic research and scientific papers
Oxidative diamination of alkenes with ureas as nitrogen sources: Mechanistic pathways in the presence of a high oxidation state palladium catalyst
Muniz, Kilian,Hoevelmann, Claas H.,Streuff, Jan
, p. 763 - 773 (2008/09/19)
A first palladium-catalyzed intramolecular diamination of unfunctionalized terminal alkenes has recently been reported. This study investigates the details of its mechanistic course based on NMR titration, kinetic measurements competition experiments, and deuterium labeling. It concludes a two-step procedure consisting of syn-aminopalladation with an unligated palladium(II) catalyst state followed by oxidation to palladium(IV) and subsequent C-N bond formation to give the final products as cyclic diamines. Related reactions employing sulfamides give rise to aminoalkoxy-functionalization of alkenes. This process was investigated employing deuterated alkenes and found to follow an identical mechanism where stereochemistry is concerned. It exemplifies the importance of cationic palladium(IV) intermediates prior to the final reductive elimination from palladium and proves that the nucelophile for this step stems from the immediate coordination sphere of the palladium(IV) precursor. These results have important implications for the general development of alkene 1,2-difunctionalization and for the individual processes of aminopalladation and palladium-catalyzed Calkyl-N bond formation.
Metal-free oxidative cyclization of urea-tethered alkenes with hypervalent iodine
Cochran, Brian M.,Michael, Forrest E.
supporting information; experimental part, p. 5039 - 5042 (2009/05/31)
(Chemical Equation Presented) A metal-free oxidative cyclization of ureas onto unactivated alkenes using iodosylbenzene and an acid promoter is described. The products isolated are predominantly bicyclic isoureas resulting from an intramolecular oxyamination reaction. The acid type and urea substitution have a strong effect on the product formed. A variety of substrates form the isourea with high diastereoselectivity via syn addition including di- and trisubstituted alkenes. Hydrolysis of the isourea gives access to new diastereomerically pure prolinol derivatives.
Exploring the nickel-catalyzed oxidation of alkenes: A diamination by sulfamide transfer
Muniz, Kilian,Streuff, Jan,Hoevelmann, Claas H.,Nunez, Ana
, p. 7125 - 7127 (2008/09/17)
(Chemical Equation Presented) Nickel can oxidize, too! Nickel (II) salts such as nickel chloride and nickel acetylacetonate catalyze the intramolecular diamination of alkenes with urea and guanidine derivatives as well as sulfamides as nitrogen sources. T
Palladium(II)-catalyzed intramolecular diamination of unfunctionalized alkenes
Streuff, Jan,Hoevelmann, Claas H.,Nieger, Martin,Muniz, Kilian
, p. 14586 - 14587 (2007/10/03)
Intramolecular diamination reactions are described which yield cyclic ureas as direct products of an oxidative alkene transformation in the presence of palladium acetate and iodosobenzene diacetate as terminal oxidant. The reaction is truly catalytic in metal catalyst and represents the proof of principle for this elusive type of alkene oxidation. Copyright
