91354-09-5Relevant articles and documents
Visible-Light-Promoted, Catalyst-Free Gomberg-Bachmann Reaction: Synthesis of Biaryls
Lee, Juyoung,Hong, Boseok,Lee, Anna
, p. 9297 - 9306 (2019/08/12)
Biaryls were synthesized via a novel visible-light-promoted Gomberg-Bachmann reaction that does not require a photosensitizer or any metal reagents. The formation of an electron donor-acceptor complex between aryl diazonium salts and pyridine allows, under visible-light irradiation, the synthesis of biaryls in moderate-to-high yields.
Structure-Affinity Relationships (SARs) and Structure-Kinetics Relationships (SKRs) of Kv11.1 Blockers
Yu, Zhiyi,Van Veldhoven, Jacobus P. D.,Louvel, Julien,'T Hart, Ingrid M. E.,Rook, Martin B.,Van Der Heyden, Marcel A. G.,Heitman, Laura H.,IJzerman, Adriaan P.
supporting information, p. 5916 - 5929 (2015/08/24)
Kv11.1 (hERG) blockers with comparable potencies but different binding kinetics might display divergent pro-arrhythmic risks. In the present study, we explored structure-kinetics relationships in four series of Kv11.1 blockers next to their structure-affinity relationships. We learned that despite dramatic differences in affinities and association rates, there were hardly any variations in the dissociation rate constants of these molecules with residence times (RTs) of a few minutes only. Hence, we synthesized 16 novel molecules, in particular in the pyridinium class of compounds, to further address this peculiar phenomenon. We found molecules with very short RTs (e.g., 0.34 min for 37) and much longer RTs (e.g., 105 min for 38). This enabled us to construct a kon-koff-KD kinetic map for all compounds and subsequently divide the map into four provisional quadrants, providing a possible framework for a further and more precise categorization of Kv11.1 blockers. Additionally, two representative compounds (21 and 38) were tested in patch clamp assays, and their RTs were linked to their functional IC50 values. Our findings strongly suggest the importance of the simultaneous study of ligand affinities and kinetic parameters, which may help to explain and predict Kv11.1-mediated cardiotoxicity.
Mild and selective deprotection method of acetylated steroids and diterpenes by dibutyltin oxide
Wang, Shao-Min,Zhang, Yan-Bing,Liu, Hong-Min,Yu, Guo-Bin,Wang, Ke-Rang
, p. 26 - 30 (2007/10/03)
Dibutyltin oxide (DBTO) was first utilized for the deacetylation of steroid and diterpene esters. The results showed the deprotection of acetylated steroids and diterpenes separately with moderate catalysis dibutyltin oxide in methanol selectively removed part acetyl groups of these substrates, whereas several functional groups of the steroids and diterpenes were retained and neither isomerization nor degradation of these substrates was observed. It seems that the acetyl groups with lower steric hindrance or near carbonyl, alkoxy, or hydroxyl groups can be cleaved by the reaction, whereas the acetyl groups with higher steric hindrance or without carbonyl, alkoxy, or hydroxyl groups neighboring were retained under the same conditions. One of the interesting results obtained was the selective hydrolysis of the 3β-O-acetyl group in the presence of the 6β group in 3β,6β-Di-O-acetyl-5α-hydroxypregn-16-en-20-one. This allows for subsequent introduction of one unit at C-3 and the other unit at C-6. This procedure is useful for the synthesis of a series of closely related isomers of 3β,5α,6β-trihydroxypregn-16-en-20-one and other widespread polyhydroxysteroids in marine organisms and some terrestrial species.
Pd-catalyzed Kumada-Corriu cross-coupling reactions at low temperatures allow the use of Knochel-type Grignard reagents
Martin, Ruben,Buchwald, Stephen L.
, p. 3844 - 3845 (2008/02/02)
A catalyst system able to operate at temperatures as low as -65 °C for the Pd-catalyzed Kumada-Corriu cross-coupling reaction is described. This unprecedented level of activity allows the use of highly functionalized (Knochel-type) Grignard reagents. Additionally, the tolerance of the protocol toward a wide variety of functional groups allows for the synthesis of valuable compounds, including heterocyclic or polyfluoro biaryls. Copyright
Aryl radicals from hexazadienes and tetrazenes
Mackay, Donald,McIntyre, Deane Douglas
, p. 990 - 999 (2007/10/02)
Aryl radicals are produced from both ends of the hexazadienes 1 and 2 and from the tetrazene 3, either thermally or photolytically.They attack aromatic compounds in the nucleus, the yield of biaryl being in the range 40-70percent, though it can be made nearly quantitative by using m-dinitrobenzene as additive.The aryl radicals also oxidize 2-propanol to acetone, the reaction products being the halogenobenzene and 1,2-diacetylhydrazine.Photolysis of 1 goes mainly by way of the tetrazene 3, and this may also be a significant pathway in the thermal reaction.Azodiacetylis an intermediate in the thermal reaction of 1 with 2-propanol and may be generally so in all its reactions.Radical induced decomposition is believed to be important in the reactions of 1, 2, and 3, and it is probably responsible for the formation of 1-acetyl-1-arylhydrazines, routinely produced in yields up to 25percent.
