- Synthesis of 3-substituted 2-cyclohexenones through umpoled functionalization
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A new protocol to obtain 3-substituted 2-cyclohexenones, was developed by reversing the chemical reactivity of 2-cyclohexenone. One-pot synthesis of 3-substituted 2-cyclohexenones can be achieved by treatment of 3-phenylthiosilyl enol ether with a mixture of t-BuLi/HMPA that allows hydrogen-selective exchange in presence of reactive electrophiles such as aldehydes, ketones and alkyl halides. This affords the corresponding product in moderate overall yield, after silyl enol ether cleavage and concomitant thiophenol elimination initiated with TBAF.
- Lechuga-Eduardo, Harim,Zarza-Acu?a, Eduardo,Romero-Ortega, Moisés
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p. 3234 - 3237
(2017/07/27)
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- Synthesis of Functionalized Ring C of Escobarines
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A synthetic strategy was developed for the preparation of α-ethynyl-α,β-epoxy-β-formyl- and α-ethynyl-α,β-epoxy-β-(hydroxymethyl)cyclohexanone from cyclohexenone as a model study in a proposed synthesis of escobarines. This highly functionalized ring is f
- Lechuga-Eduardo, Harim,Romero-Ortega, Moises,Olivo, Horacio F.
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- Synthesis of an epoxyquinol analog: Efficient methodology for the insertion of side chains into cyclohexenone cores
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A novel epoxyquinol analog was prepared by molecular simplification of monomeric and dimeric scaffolds. A feasible methodology for the insertion of side chains into cyclohexenone skeleton was developed. Insertion of the hydroxymethyl side chain was achiev
- Heguaburu, Viviana,Schapiro, Valeria,Pandolfi, Enrique
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scheme or table
p. 6921 - 6923
(2011/02/27)
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- Preparation and Reactivity of Highly Functionalized Organometallics at the α Position of Oxygen or Nitrogen
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α-Halogenoalkyl carboxylates (FG-R1CH(X)(OCOR2); FG = COOR, CN, SR; X = I, Br) were readily prepared by the addition of an acid chloride or bromide (R2COX; X = Br or Cl) to an aldehyde (FG-RCHO) in the presence of a catalytic amount of ZnCl2.They insert efficiently zinc dust in THF-DMSO (X = Br, 8 - 10 deg C, 6 - 10 h) affording the corresponding zinc organometallics at the α position to oxygen FG-RCH(ZnBr)(OAc).After the addition of the THF-soluble copper salt CuCN*2LiCl, the corresponding copper reagents FG-RCH(Cu(CN)ZnBr)(OAc) are formed and reacted with variousclasses of electrophiles such as acid chlorides, aldehydes, enones, allylic and alkynyl halides, activated alkynes, nitro olefins and alkylidenemalonates providing polyfunctional molecules in excellent yields.Similarly, zinc organometallics at the α position to the nitrogen of cyclic imides were prepared by the zinc insertion to cyclic α-chloromethyl (or α-chloroethyl) imides.After their transmetalation to the corresponding copper organometallic ((R1CO)2NCH(R)(Cu(CN)ZnCl); R = Me or H), they were reacted with allylic and alkynyl halides and ethyl propiolate affording polyfunctional imides.The reaction of cyclic N-(chloromethyl)imides with aldehydes in the presence of chromium(II) chloride in THF furnishes protected amino alcohols in 36 - 95percent yield.
- Knochel, Paul,Chou, Tso-Sheng,Jubert, Carole,Rajagopal, Duddu
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p. 588 - 599
(2007/10/02)
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- Nucleophilic Reactivity of Zinc and Copper Carbenoids. 2
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The rectivity of the new zinc and copper carbenoids PivOCH2Cu(CN)ZnI (4) and ICH2Cu*ZnI2 (5) toward various electrophiles has been investigated.Of special interest is the direct and highly stereoselective conversion of allylic bromides to the corresponding homoallylic iodides by using the reagent ICH2Cu*ZnI2
- Knochel, Paul,Chou, Tso-Sheng,Chen, Huai Gu,Yeh, Ming Chang P.,Rozema, Michael J.
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p. 5202 - 5204
(2007/10/02)
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