Direct allylation of aromatic and α,β-unsaturated carboxamides under ruthenium catalysis
作者:Mirim Kim、Satyasheel Sharma、Neeraj Kumar Mishra、Sangil Han、Jihye Park、Minyoung Kim、Youngmi Shin、Jong Hwan Kwak、Sang Hoon Han、In Su Kim
DOI:10.1039/c4cc03354j
日期:——
The ruthenium-catalyzed oxidative allylation of aromatic and alpha,beta-unsaturated carboxamides with allylic carbonates is described. These transformations proceed readily with complete linear gamma-selectivity of substituted allylic carbonates.
An inexpensive ruthenium‐catalyzed direct C–H olefination of aromatic carboxamides with allyl acetate was developed. This external oxidant‐free protocol provided an efficient route for the synthesis of useful trans‐styrene derivatives in high to excellent yields. The olefination reaction exhibited excellent regioselectivities and allowed the presence of a wide range of functional groups, such as OMe
Methods and materials for the imaging of cells and tissues containing active proteases such as cathepsin are disclosed. The present materials include activity based probes that bind to an enzyme and are subsequently cleaved. Cleavage results in covalent attachment of a fluorescent signal to a target protease due to removal of a quenching group which, when present on the probe causes altered or no fluorescence. The probes are non-peptidic, small molecule scaffolds linked to a reactive acyloxymethyl ketone group, a fluorophore and a quencher. The probes are cell permeable and may use, for example, a QSY21 (CAS 304014-13-9) quencher and a cyanine dye. The probes form covalent bonds with the active site of cysteine cathepsins, proteases that are upregulated at the tumor boundaries with normal tissue and at sites of inflammation.