Selective Co/Ti Cooperatively Catalyzed Biaryl Couplings of Aryl Halides with Aryl Metal Reagents
摘要:
Various aryl bromides or chlorides, including those bearing a free COOH, OH, CONHR, and SO2NHR group, coupled with aryl magnesium or lithium reagents in the presence of 7.5 mol % CoCl2/15 mol % PBu3 and substoichiometric Ti(OEt)(4) (40 mol % to ArM) at room temperature in high yields with high chemo- and regioslectivity. This simple reaction represents the first example of Co/Ti cooperative catalysis which plays a key role in suppressing undesired homocouplings.
Synthesis, biological evaluation, and molecular modeling studies of methylene imidazole substituted biaryls as inhibitors of human 17α-hydroxylase-17,20-lyase (CYP17)—Part II: Core rigidification and influence of substituents at the methylene bridge
Thirty-five novel substituted imidazolyl methylene biphenyls have been synthesized as CYP17 inhibitors for the potential treatment of prostate cancer. Their activities have been tested with recombinant human CYP17 expressed in Escherichia coli. Promising compounds were tested for selectivity against CYP11B1, CYP11B2, and hepatic CYP enzymes 3A4, 1A2, 2B6 and 2D6. The core rigidified compounds (30-35)
An efficient water-soluble surfactant-type palladium catalyst for Suzuki cross-coupling reactions in pure water at room temperature
作者:Pei Qiu、Jing Yang Zhao、Xu Shi、Xin Hong Duan
DOI:10.1039/c6nj00377j
日期:——
An in situ-generated Pd catalyst with a bidentate phosphine-type zwitterionic surfactant as a ligand showed high catalytic activity in the Suzuki reactions.
A class of confined chiral hypervalent iodines have been designed and developed by incorporating two sterically demanding BINOL-derived units, which form the second-layer chiral environment, into the iodine-containing molecules to lock down the conformation of the catalyst and indirectly create a compact chiral environment around the active site. Good-to-excellent enantioselectivities have been achieved