Pyridyl-Cyclopentadiene Re(CO)2+ Complexes as a Compact Core System for SPECT Ligand Development
摘要:
An eta'eta(5)-rhenium complex has been prepared, starting from a CpRe(CO)(3) complex substituted with a pendant aromatic amine. This unique complex has potential application as a surrogate for a technetium-99m complex, a common radioisotope for biomedical imaging applications. Chelation occurred via photochemical decarbonylation of the rhenium, which opened a binding site for the aromatic amine.
Metal-free C(sp<sup>3</sup>)–H bond sulfonyloxylation of 2-alkylpyridines and alkylnitrones
作者:Chang-Sheng Wang、Pierre H. Dixneuf、Jean-François Soulé
DOI:10.1039/c8ob01075g
日期:——
Pyridin-2-ylmethyl tosylate derivatives are obtained in high yields from 2-alkylpyridine 1-oxides via a [3,3]-sigmatropicrearrangement of the adduct between 2-alkylpridine 1-oxides with benzenesulfonyl chlorides. Moreover, alkylnitrones also undergo [3,3]-sigmatropicrearrangement to give α-tosylated ketones after hydrolysis. Substitution reactions with nucleophiles then lead to diverse useful functionalizations
Ion Pair-Directed Regiocontrol in Transition-Metal Catalysis: A Meta-Selective C–H Borylation of Aromatic Quaternary Ammonium Salts
作者:Holly J. Davis、Madalina T. Mihai、Robert J. Phipps
DOI:10.1021/jacs.6b08164
日期:2016.10.5
interactions to direct transition-metal catalysis is a potentially powerful yet relatively underexplored strategy, with most investigations thus far focusing on using hydrogen bonds as the controlling element. We have developed an ion pair-directed approach to controlling regioselectivity in the iridium-catalyzed borylation of two classes of aromatic quaternaryammonium salts, leading to versatile meta-borylated
benzyl halides and sulfonates imparts unique reactivity at the benzylic carbon atom. Photoredox sp3-sp3 cross-coupling proved ineffective for coupling p-methoxybenzyl chloride (PMBCl), leading to a new strategy for the sp3-sp3 cross-coupling of benzyl halides and sulfonates. This strategy involved LiCl-accelerated synthesis of a Grignard reagent followed by a copper-catalyzed cross-coupling. The conditions
The invention provides compounds of formula (I)
wherein R
1
, R
3
, L
1
, L
2
, G
1
, G
2
, A and m are as defined in the specification and optical isomers, racemates and tautomers thereof, and pharmaceutically acceptable salts thereof; together with processes for their preparation, pharmaceutical compositions containing them and their use in therapy. The compounds are inhibitors of microsomal prostaglandin E synthase-1.