Adição Nucleofílica de Sais de Potássio de Organotrifluoroboratos à Íons N-Acilimínio

Adição Nucleofílica de Sais de Potássio de Organotrifluoroboratos à Íons N-Acilimínio

Alternative title Nucleophilic Addition of Potassium Organotrifluoroborate salts to N-Acyliminium Ions
Author Ferreira, Fernando da Paz Autor UNIFESP Google Scholar
Advisor Stefani, Helio Alexandre Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Abstract In this work, we developed a new methodology for the stereoselective acquisition of substituted pyrrolydin-2-ones in the 5 position through the addition of potassium organotrifluoroborate salts to cyclic N-acyliminium cations. The á-amidoalkylation reactions involve lactams derivative tartaric acid – (3R, 4R, 5R)-3,4-bis-(acetoxy)-5- hidroxy-1-benzyl-2-pyrrolydinone and alkyl, aryl, heteroaryl, allyl and alkynyl potassium organotrifluoroborate salts, providing substituted pyrrolydin-2-ones in the á position of 1 ab, with yield variable of 63% to 87% and diastereoselectivity of moderate to good, where the diastereoisomer syn were obtained preferentially in the cases where of the nucleophilic carbon have sp and sp2 hybridization and occurring the inversion of the diastereoselectivity, that is, preferentially the diastereoisomer anti in the case of carbon hybridization sp3. The relative stereochemistry syn/anti of the majority products were deduce through of the spectroscopic data of 1H and 13C NMR. The salts of heteroaryl, aryl, alkyl and acetylenes compounds were obtained through the generation of the respective organomagnesium and organolitium anions followed by the addition of trimethylborate at low temperature and further reaction with aqueous KHF2.

Neste trabalho, desenvolvemos uma nova metodologia para a obtencao estereosseletiva de pirrolidin-2-onas substituidas na posicao 5 atraves de adicao de sais de potassio de organotrifluoroboratos a cations N-aciliminio ciclicos. As reacoes de ƒ¿- amidoalquilacao envolvem lactamas derivadas do acido tartarico . (3R,4R)-3,4,5-tris- (acetoxi)-1-benzil-2-oxopirrolidin-3-il, (3R,4R,5R)-3,4-bis-(acetoxi)-5-hidroxi-1-benzil-2- pirrolidinona e sais de potassio de organotrifluoroboratos alquilicos, arilicos, heteroarilicos, alilicos e alquinilicos, fornecendo pirrolidin-2-onas substituidas na posicao ƒ¿ de 1 a-b, com rendimentos que variam de 63% a 87% e com diastereosseletividade de moderadas a boas, onde o diastereoisomero syn foi obtido preferencialmente nos casos onde o carbono nucleofilico tem hibridizacao sp e sp2 e ocorrendo a inversao da diastereosseletividade, isto e, preferencialmente o diastereoisomero anti nos casos de carbonos hibridizados sp3. A estereoquimica relativa syn/anti dos produtos majoritarios foi inferida atraves dos dados espectroscopicos de RMN de 1H e 13C. Os sais de heteroaril, aril, alquil e acetilênicos foram obtidos através da geração dos respectivos ânions organomagnésio e organolítio seguido pela adição de trimetilborato à baixa temperatura e posterior reação com KHF2 aquoso.
Keywords substituido-2-pirrolidinonas
substituted-2-pyrrolidinones
Alfa-amidoalquilacao
Alpha-amidoalkylation
Organotrifluoroborate
Organotrifluoroborato
Ions N-acyliminio
N-acyliminium Ions
Language Portuguese
Date 2009-06-24
Published in FERREIRA, Fernando da Paz. Adição Nucleofílica de Sais de Potássio de Organotrifluoroboratos à Íons N-Acilimínio. 2009. Dissertação (Mestrado) - Universidade Federal de São Paulo (UNIFESP), São Paulo, 2009.
Publisher Universidade Federal de São Paulo (UNIFESP)
Access rights Open access Open Access
Type Dissertation
URI http://repositorio.unifesp.br/handle/11600/8875

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