85355-52-8Relevant academic research and scientific papers
Arenediazonium o-benzenedisulfonimides in Heck-type arylation of allylic alcohols
Barbero, Margherita,Cadamuro, Silvano,Dughera, Stefano
, p. 3443 - 3452 (2008/02/12)
Arenediazonium o-benzenedisulfonimides were reacted with primary and secondary allylic alcohols. The reactions, carried out in aqueous ethanol in the presence of palladium(II) acetate as precatalyst and sodium hydrogen carbonate as base, gave the arylation products with good overall conversion. In all cases, the major products were the β-arylated carbonyl derivatives. The o-benzene-disulfonimide was recovered in high yield from all the reactions, and it was recycled for the preparation of other salts. Georg Thieme Verlag Stuttgart.
New Types of Very Efficient Photolabile Protecting Groups Based upon the [2-(2-Nitrophenyl)propoxy]carbonyl (NPPOC) Moiety
Buehler, Sigrid,Lagoja, Irene,Giegrich, Heiner,Stengele, Klaus-Peter,Pfleiderer, Wolfgang
, p. 620 - 659 (2007/10/03)
Based upon the photolabile [2-(2-nitrophenyl)propoxy]carbonyl group (NPPOC), a large number of modified 2-(2-nitrophenyl)propanol derivatives substituted at the phenyl ring (see 23-34 and 57-76) as well as at the side-chain (see 85-92 and 95-98) were synthesized to improve the photoreactivity of this new type of photolabile entity. The phenyl moiety was also exchanged by the naphthalenyl group (see 102, 103, 105, 108, 110, 113, and 114), the thienyl substituent (see 115, 117, 118, and 120), and the benzothienyl substituent (see 121). The 2-(2-nitroaryl- and heteroaryl) propanols were converted with diphosgene into the corresponding carbonochloridates, which reacted subsequently with thymidine to the thymidine 5′-(protected carbonates) 123-178 as the main reaction products. In several cases, the corresponding 3′-carbonates and 3′,5′ -dicarbonates 179-212 were also isolated and characterized. Photolysis studies under standardized conditions (see Table) indicated that the rate of photocleavage varies in a broad range depending on the substituents. So far, the thymidine 5′-[2-(5-halo-2-nitrophenyl)propyl carbonates] 127-129, 5′-[2-(nitro[1,1′-biphenyl]3-yl)propyl carbonates] 136-139, 5′-{2-[2-nitro-5-(thianthren-1-yl)phenyl]propyl carbonate} (140), 5′-[2-(5-naphthalenyl-2-nitrophenyl)propyl carbonates] 141 and 142, and 5′-[2-(2-nitro-5-thienylphenyl)propyl carbonates] 143 and 144 showed the best properties regarding fast and uniform deprotection. Since the nucleobases of 213-215 do not influence the photocleavage features, in general, the new type of photolabile building blocks allows in form of their 3′ -phosphoramidites the photolithographic formation of high-quality biochips.
Electrochemical synthesis of nitroaromatic ketones
Gallardo, Iluminada,Guirado, Gonzalo,Marquet, Jordi
, p. 261 - 267 (2007/10/03)
Nitroaromatic ketones are readily prepared by nucleophilic aromatic substitution of hydrogen in nitroarenes by electrochemical oxidation. Carbanions of various ketones were added to selected nitroarenes in DMF/ketone mixtures leading to formation of the o
An annulative approach to highly substituted indoles: Unusual effect of phenolic additives on the success of the arylation of ketone enolates
Rutherford, Jennifer L.,Rainka, Matthew P.,Buchwald, Stephen L.
, p. 15168 - 15169 (2007/10/03)
A novel palladium-catalyzed arylation of ketone enolates with o-nitrohaloarenes was achieved through the addition of phenol additives. The mild reaction conditions employed allowed for the inclusion of a wide variety of functional groups in both substrates to be tolerated. The products of this reaction were then readily reductively cyclized to give highly substituted indoles in moderate to excellent overall yields. Copyright
Synthesis of Substituted Indoles via Meerwein Arylation
Raucher, Stanley,Koolpe, Gary A.
, p. 2066 - 2069 (2007/10/02)
A new method for the synthesis of substituted indoles is detailed.Meerwein arylation of 4- and 6-substituted 2-nitrobenzenediazonium chlorides with vinyl acetate or vinyl bromide and subsequent reductive cyclization of the resulting adducts affords the corresponding 6- and 4-substituted (CH3, OCH3, Cl, Br, CF3) indoles.The diazonium bisulfates of weakly basic 2-nitroanilines (4-Cl, 6-Br, 4-CF3) gave higher yields of Meerwein arylation adducts than the corresponding diazonium chlorides.Coupling of 2-nitrobenzenediazonium chloride with 2-acetoxy-1-alkenes followed byreductive cyclization affords 2-alkylindoles.
