first example of near-room-temperature α-arylation of benzo[b]thiophenes is reported. The discovery rests on the observation of a switch in α-/β-regioselectivity at different loadings of Pd2(dba)3·CHCl3 in the coupling between benzo[b]thiophene and 4-iodotoluene. We show that this unprecedented regioselectivity switch is driven by a Ag(I)-mediated C–H activation at the α-C–H position, which becomes the
HETEROCYCLIC INDENE DERIVATIVES AND THEIR RADIOISOTOPE LABELED COMPOUNDS FOR IMAGING BETA-AMYLOID DEPOSITION
申请人:JEONG Jae Min
公开号:US20080299041A1
公开(公告)日:2008-12-04
The invention is directed to heterocyclic indene derivatives useful for β-amyloid plaque imaging, their radiolabeled compounds and their preparation methods. The compounds of the invention are easily labeled with radioisotopes and have high affinities to β-amyloid depositions, thus they facilitate diagnosis of Alzheimer's disease by imaging the distribution of β-amyloid depositions.