- C-H carbene insertion of α-diazo acetamides by photolysis in non-conventional media
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(Chemical Equation Presented) Light from a mercury vapor high-pressure lamp was used to induce the photolytic decomposition of α-diazo acetamides in hexane and in nonconventional media such as water or a film. The corresponding a- and/or γ-lactams were ob
- Candeias, Nuno R.,Gois, Pedro M. P.,Veiros, Luis F.,Afonso, Carlos A. M.
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p. 5926 - 5932
(2008/12/21)
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- A convenient method for the preparation of chiral phosphonoacetamides and their Horner-Wadsworth-Emmons reaction
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Chiral phosphonoacetamides bearing (S)-(α-methylbenzyl)benzylamine, (S,S)-bis(α-methylbenzyl)amine, l-phenylglycine methyl ester and l-phenylglycinol were easily prepared in good yield by means of the Michaelis-Arbuzov reaction of chiral bromoacetamides obtained in quantitative yield, with trimethyl phosphite, which under Horner-Wadsworth-Emmons conditions with several aryl and alkyl aldehydes under Masamune-Roush procedure using LiCl and DBU in THF or toluene gave the corresponding chiral α,β-unsaturated amides. The present procedure is a convenient and efficient methodology for the preparation of phosphonoacetamides and chiral α,β-unsaturated amides in high E-selectivity.
- Ordonez, Mario,Hernandez-Fernandez, Eugenio,Montiel-Perez, Martin,Bautista, Rafael,Bustos, Paola,Rojas-Cabrera, Haydee,Fernandez-Zertuche, Mario,Garcia-Barradas, Oscar
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p. 2427 - 2436
(2008/03/13)
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- Stereoselective alkylation of C2-symmetric chiral N- phthaloylglycinamides in the preparation of enantiopure α-amino acids
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The novel, chiral glycinamides (S,S)-3 and (S,S)-4 were prepared in good yields from C2-symmetric chiral amines (S,S)-1 and (S,S)-2, respectively. Enolate formation and addition to methyl iodide and benzyl bromide proceeded in good yield and high diastereoselectivity, especially in the presence of LiCl or DMPU. Removal of the phthaloyl protecting group with hydrazine, followed by hydrolysis with 6N HCl, converted the benzylated product (S,S,S)- 7 to enantiopure (S)-phenylalanine. (C) 2000 Elsevier Science Ltd.
- Reyes, Adelfo,Juaristi, Eusebio
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p. 1411 - 1423
(2007/10/03)
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