[RuIV(F20-TPP)Cl2] efficiently catalysed inter- and intra-molecular nitrene insertion into sp3 C–H bonds of hydrocarbons using phosphoryl azides as nitrene sources
作者:Wenbo Xiao、Jinhu Wei、Cong-Ying Zhou、Chi-Ming Che
DOI:10.1039/c3cc41110a
日期:——
[Ru(IV)(F20-TPP)Cl2][H2(F20-TPP) = meso-tetrakis(pentafluorophenyl)porphyrin] is an active catalyst for both inter- and intra-molecular nitreneinsertion into sp(3) C-H bonds of hydrocarbons in good to high product yields using phosphoryl azides as nitrene sources.
A simple method for direct metal-free C–H amination of unactivated hydrocarbons using easy-handling diacetoxy-λ3-bromane and triflylamide or sulfamate esters was developed.
Rhodium-catalyzed intermolecular C(sp<sup>3</sup>)–H amination in a purely aqueous system
作者:Xunbo Lu、Yufeng Shi、Fangrui Zhong
DOI:10.1039/c7gc03149a
日期:——
An efficient Rh-catalyzed intermolecularC(sp3)–Hamination in a purely aqueous system is developed for the first time. This methodology features environmental benignity, broad substrate scope and versatility in late-stage functionalization of several biologically important molecules. Such an oxidation protocol provides easy access to various aliphatic amine derivatives in an efficient and sustainable
Catalytic Intermolecular Amination of C−H Bonds: Method Development and Mechanistic Insights
作者:Kristin Williams Fiori、J. Du Bois
DOI:10.1021/ja0650450
日期:2007.1.1
y Reaction methodology for intermolecular C-H amination of benzylic and 3 degrees C-H bonds is described. This process uses the starting alkane as the limiting reagent, gives optically pure tetrasubstituted amines through stereospecific insertion into enantiomeric 3 degrees centers, displays high chemoselectivity for benzylic oxidation, and enables the facile preparation of isotopically enriched N-15-labeled compounds. Access to substituted amines, amino alcohols, and diamines is thereby made possible in a single transformation. Important information relevant to understanding the initial steps in the catalytic cycle, reaction chemoselectivity, the nature of the active oxidant, and pathways for catalyst inactivation has been gained through mechanistic analysis; these studies are also presented.
<i>O</i>- and <i>N</i>-Sulfations of Carbohydrates Using Sulfuryl Imidazolium Salts
作者:Laura J. Ingram、Ahmed Desoky、Ahmed M. Ali、Scott D. Taylor
DOI:10.1021/jo9014112
日期:2009.9.4
A series of sulfuryl imidazolium salts (SISs) were prepared and examined as reagents for incorporating trichloroethyl-protected sulfate esters into carbohydrates. The SIS that contained a 1,2-dimethylimidazolium moiety (SIS 9) proved to be a superior sulfating compared to SISs bearing no alkyl groups or bulkier alkyl groups on the imidazolium ring. Difficult O-sulfations that required prolonged reaction times and a large excess of the SIS bearing a 1-methylimidazolium group (SIS 5) were achieved in high yield using less than half the amount of SIS 9 in less time. Certain N-sulfated compounds that were practically inaccessible using SIS 5 were obtained in excellent yield using SIS 9.