26480-90-0Relevant academic research and scientific papers
Convenient synthesis of volatile Streptomyces lactones
Amonkar, Chandan P.,Tilve, Santosh G.,Parameswaran
, p. 2341 - 2344 (2005)
A convenient three-step synthetic approach towards 3-alkyl-5-methyl-2[5H] furanones is described. The steps involved in the synthesis are domino primary alcohol oxidation-Wittig reaction, acid-catalysed lactonisation and isomerisation. This synthetic appr
Catalytic Synthesis of 8-Membered Ring Compounds via Cobalt(III)-Carbene Radicals
Lankelma, Marianne,Zhou, Minghui,de Bruin, Bas,van der Vlugt, Jarl Ivar
supporting information, p. 11073 - 11079 (2020/04/29)
The metalloradical activation of o-aryl aldehydes with tosylhydrazide and a cobalt(II) porphyrin catalyst produces cobalt(III)-carbene radical intermediates, providing a new and powerful strategy for the synthesis of medium-sized ring structures. Herein we make use of the intrinsic radical-type reactivity of cobalt(III)-carbene radical intermediates in the [CoII(TPP)]-catalyzed (TPP=tetraphenylporphyrin) synthesis of two types of 8-membered ring compounds; novel dibenzocyclooctenes and unprecedented monobenzocyclooctadienes. The method was successfully applied to afford a variety of 8-membered ring compounds in good yields and with excellent substituent tolerance. Density functional theory (DFT) calculations and experimental results suggest that the reactions proceed via hydrogen atom transfer from the bis-allylic/benzallylic C?H bond to the carbene radical, followed by two divergent processes for ring-closure to the two different types of 8-membered ring products. While the dibenzocyclooctenes are most likely formed by dissociation of o-quinodimethanes (o-QDMs) which undergo a non-catalyzed 8π-cyclization, DFT calculations suggest that ring-closure to the monobenzocyclooctadienes involves a radical-rebound step in the coordination sphere of cobalt. The latter mechanism implies that unprecedented enantioselective ring-closure reactions to chiral monobenzocyclooctadienes should be possible, as was confirmed for reactions mediated by a chiral cobalt-porphyrin catalyst.
Olefin-Directed Palladium-Catalyzed Regio- and Stereoselective Oxidative Arylation of Allenes
Zhu, Can,Yang, Bin,Jiang, Tuo,B?ckvall, Jan-E.
supporting information, p. 9066 - 9069 (2015/08/03)
An olefin-directed palladium-catalyzed oxidative regio- and stereoselective arylation of allenes to afford 1,3,6-trienes has been established. A number of functionalized allenes, including 2,3- and 3,4-dienoates and 3,4-dienol derivatives, have been inves
Expedient synthesis of α-substituted α,β-unsaturated γ-amino acids (dipeptide mimetics); Wittig reaction of α-amino aldehydes with α- substituted alkoxycarbonyl phosphoranes
Scholz, Dieter,Weber-Roth, Sabine,Macoratti, Elena,Francotte, Eric
, p. 1143 - 1155 (2007/10/03)
Reacting ethoxycarbonyl triphenyl phosphorane with activated alkylhalides in chloroform gave the ylides 4 - 12. They react smoothly and in general without racemisation with α-amino aldehydes resulting in the dipeptide mimetics 15 - 25. Exceptions are the
Synthesis of β-enaminoesters and lactams by Michael addition of N- benzylaniline to new allenic esters and lactams
Ibrahim-Ouali, Malika,Sinibaldi, Marie-Eve,Troin, Yves,Gardette, Daniel,Gramain, Jean-Claude
, p. 1827 - 1848 (2007/10/03)
The synthesis of original allenic lactams 2 and allenic esters 5 is presented and their Michael condensation with N-benzylaniline described.
New Synthesis of Catalpalactone
Chordia, Mahendra D.,Narasimhan, Nurani S.
, p. 371 - 376 (2007/10/02)
Various alkylidenephthalides (E- and Z-5, 6 and 7) were prepared by Wittig reaction of phosphoranes 4a, 4b and 4c respectively with phthalic anhydride.The products were then lactonised, using chloro(trimethyl)silane and sodium iodide, to the corresponding
A CONVENIENT TWO-STEP SYNTHESIS OF 3-ALLYLCOUMARINS AND THEIR BENZODERIVATIVES
Mali, Raghao S.,Tilve, Santosh G.,Yeola, Suresh N.,Manekar, Anita R.
, p. 121 - 127 (2007/10/02)
A convenient, high yield, two step synthesis of 3-allylcoumarins and their benzo derivatives is described from 2-hydroxybenzaldehydes.The benzaldehydes (2a-j) on reaction with phosphorane 3 provide E-ethyl-α-allylcinnamates (4a-j) in high yields.These est
