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Titolo:
CATALYTIC ASYMMETRIC C-C BOND-FORMING REA CTION USING OPTICALLY-ACTIVE RARE-EARTH COMPLEX
Autore:
SHIBASAKI M; SASAI H;
Indirizzi:
UNIV TOKYO,FAC PHARMACEUT SCI,7-3-1 HONGO,BUNKYO KU TOKYO 113 JAPAN
Titolo Testata:
Yuki Gosei Kagaku Kyokaishi
fascicolo: 11, volume: 51, anno: 1993,
pagine: 972 - 984
SICI:
0037-9980(1993)51:11<972:CACBRC>2.0.ZU;2-S
Fonte:
ISI
Lingua:
JPN
Soggetto:
ORGANIC-SYNTHESIS; CHEMISTRY; YTTRIUM; EFFICIENT; REAGENTS;
Keywords:
RARE EARTH ELEMENT; LANTHANUM BINOL COMPLEX; NITROALDOL REACTION; LASER DESORPTION IONIZATION TIME-OF-FLIGHT MASS SPECTROMETRY; METOPROLOL; PROPRANOLOL; BASIC CATALYST; ASYMMETRIC REACTION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
31
Recensione:
Indirizzi per estratti:
Citazione:
M. Shibasaki e H. Sasai, "CATALYTIC ASYMMETRIC C-C BOND-FORMING REA CTION USING OPTICALLY-ACTIVE RARE-EARTH COMPLEX", Yuki Gosei Kagaku Kyokaishi, 51(11), 1993, pp. 972-984

Abstract

Newly synthesized optically active rare earth complexes made possiblea catalytic asymmetric nitroaldol reaction for the first time, givingnitroaldols in up to 95% ee. The catalyst complexes were prepared from rare earth (La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb, and Y) trichloride, dilithium (S)-binaphthoxide, NaOH, and H2O. The presence of LiCl and H2O appeared to be essential to obtain nitroaldols of high optical purity. The application to catalytic asymmetric syntheses of beta-blockers, (S)-metoprolol and (S)-propranolol, has been also achieved. Laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) of rare earth metal BINOL complexes has suggested that all complexes are possessing one rare earth atom, three BINOL units and three Li atoms. Finally, X-ray crystallographic analyses of the Li free (Na containing) rare earth BINOL complexes (Pr, Nd and Eu) have been performed and the results were very much in agreement with the spectroscopic and analytical data. Although every Li free catalyst was not effective for asymmetric nitroaldol reactions, an addition of three molar equivalents of LiCl caused complete exchange of Na with Li resulting in the formation of an effective asymmetric catalyst.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 02/12/20 alle ore 07:59:18