“…Phenanthrenequinone [ 4, R 1 R 2 = R 3 R 4 = (CH) 4 ] and naphthoquinone [ 4, R 1 R 2 = (CH) 4 , R 3 = R 4 = H] react with 1 mol equiv of benzylidene(triphenyl)phosphorane ( 107 , R = Ph, C 6 H 4 OMe- p , C 6 H 4 Br- p ) to yield the stable o -quinone methanides 245 . While in case of 2 mol equiv, the dihydrofurans 246 are formed. ,, …”
Section: Reactions With Wittig Reagentsmentioning
confidence: 99%
“…[126][127][128] The structure of compound 160 (R 1 ) Ph, R 2 ) H, X ) NH) was identified by X-ray analysis. 128 On the other hand, imino(triphenyl)phosphorane (161) with aryldihydrofurandiones 159 (R 1 ) H; R 2 ) H, Me; X ) O) gives 6-aryl-2-[(triphenylphosphoranylidene)amino]-1,3oxazin-4-ones (162), via a thermolysis/[4 + 2]-cycloaddition, sequence involving intermediate aroylketenes. 129 The Wittig reaction of 5-aryl-2,3-furandiones 163 (R ) aryl; R 1 ) H, Br, COPh) with the phosphoranes 164 (R 2 ) H, Me, Br; R 3 ) COOMe, COMe, COC 6 H 4 -Br-4, COC 6 H 4 Cl-4) in boiling benzene forms the 2-alkylidene derivatives 165.…”
Section: Reactions With Wittig Reagentsmentioning
confidence: 99%
“…While in case of 2 mol equiv, the dihydrofurans 246 are formed. 152,157,161 On the other hand, the reaction of methylene-…”
“…Phenanthrenequinone [ 4, R 1 R 2 = R 3 R 4 = (CH) 4 ] and naphthoquinone [ 4, R 1 R 2 = (CH) 4 , R 3 = R 4 = H] react with 1 mol equiv of benzylidene(triphenyl)phosphorane ( 107 , R = Ph, C 6 H 4 OMe- p , C 6 H 4 Br- p ) to yield the stable o -quinone methanides 245 . While in case of 2 mol equiv, the dihydrofurans 246 are formed. ,, …”
Section: Reactions With Wittig Reagentsmentioning
confidence: 99%
“…[126][127][128] The structure of compound 160 (R 1 ) Ph, R 2 ) H, X ) NH) was identified by X-ray analysis. 128 On the other hand, imino(triphenyl)phosphorane (161) with aryldihydrofurandiones 159 (R 1 ) H; R 2 ) H, Me; X ) O) gives 6-aryl-2-[(triphenylphosphoranylidene)amino]-1,3oxazin-4-ones (162), via a thermolysis/[4 + 2]-cycloaddition, sequence involving intermediate aroylketenes. 129 The Wittig reaction of 5-aryl-2,3-furandiones 163 (R ) aryl; R 1 ) H, Br, COPh) with the phosphoranes 164 (R 2 ) H, Me, Br; R 3 ) COOMe, COMe, COC 6 H 4 -Br-4, COC 6 H 4 Cl-4) in boiling benzene forms the 2-alkylidene derivatives 165.…”
Section: Reactions With Wittig Reagentsmentioning
confidence: 99%
“…While in case of 2 mol equiv, the dihydrofurans 246 are formed. 152,157,161 On the other hand, the reaction of methylene-…”
“…Active aldehydes 14b,c,e,f in Table were complete after 30 min, whereas the other examples ( 14d,i,j ) gave pure products after 5 h. The isolated chalcones were primarily of trans stereochemistry, although the amide-linked chalcones 10m and n gave 30% and 20% cis isomers, respectively. The amide-linked chalcones were also prone to TFA-catalyzed dimerization . This dimerization only occurred while lyophilizing the pure products in the presence of TFA after cleavage.…”
A diverse array of 3,4-dihydro-2-pyridones 13 were produced utilizing the unique properties of solid-supported reactions to both drive the reactions to completion and isolate the desired products. The pyridones were synthesized in high purity by a simple sequence of novel steps commencing from an acetophenone-functionalized resin. The para-substituted acetophenone 9 could be anchored to the resin through either a sulfonamide or a carboxamide linkage. The sulfonamide resin 9a, which gave the best results, was treated with several aryl aldehydes and ethoxide to give a variety of chalcones 10a-k in excellent yield (82-99%) upon TFA cleavage. Addition of either methyl or allyl malonate and DBU to 10a-k afforded smoothly the Michael adducts 11a-j (70-99%) which were subsequently cyclized in one step employing acetic acid as a catalyst and several diverse amines to give pure 3,4-dihydro-2-pyridones 13a-p in moderate to excellent yields (30-98%).
“…The model reaction consisted of reacting a reactive aldehyde, such as benzaldehyde, with methyltriphenylphosphonium iodide in the presence of 5 N NaOH and benzene to give styrene in 99% yield. Phenanthroquinone can also be reacted under PTC conditions to give the mono-Wittig product [269]. Ketones are unreactive (no olefin from acetophenone).…”
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