Reductions of CO and CN groups with the systems composed of (η5-C5H5)2MoH2 and acids
摘要:
Selective reductions of organic compounds, such as carbonyl compounds and imines, using a system composed of Cp2MoH2 and acids are examined. This system can reduce the substrates under mild conditions. Extremely high diastereoselectivity was achieved in the reduction of 4-t-butylcyclohexanone. The reactivity of imines depends on their structure. Aromatic imines are found to be more reactive than aliphatic imines. (C) 1998 Elsevier Science S.A. All rights reserved.
The oxidation of α ketone imine carbanions gives primary α ketols from methylketones, and secondary α ketols from symmetric ketones. Secondary α ketols may also be isolated by oxidation of carbanions of methylketone oximes. By using manganese dioxide, these secondary ketols may be oxidized to α diketones.
Stereoselektive Synthese von Alkoholen, X. Diastereoselektive Synthese von (–)‐δ‐Multistriatin
作者:Reinhard W. Hoffmann、Wilfried Helbig
DOI:10.1002/cber.19811140812
日期:1981.8
Aus Benzyloxyacetaldehyd(3) und dem chirlalen Boronsäureester 4 erhielt man durch diastereoselektive CC–Verknüpfung den Homoallylalkohol5. Daraus wurden durch Standardoperationen der Alkohol 8 und Weiter (–)-δ-Multistriatin (1) von 97% Isomerenreinheit dargestellt.
AUS Benzyloxyacetaldehyd(3)UND DEM chirlalenBoronsäureester 4 erhielt人第三人以diastereoselektive CC-Verknüpfung巢穴Homoallylalkohol 5。Daraus wurden durch酒精标准操作8和Weiter(–)-δ-Multistriatin(1),含97%异戊二烯。
Regioselective α-alkylation of ketones with alkyl chlorides and fluorides via highly nucleophilic magnesium enamides
A magnesium enamide derived from N-2-(N′,N′-dimethylamino)ethylimine reacts with primary and secondary alkyl chlorides and fluorides to give an α-alkylated ketone in good to excellent yields upon hydrolysis of the imine moiety. Reactions of the highly nucleophilic magnesium enamide derived from an unsymmetrical ketone take place regioselectively. In addition, the C–C bond formation is stereospecific:
Multinuclear magnetic resonance study of oxaziridines
作者:Mane Čudić、Rudolf Herrmann
DOI:10.1002/mrc.1260310509
日期:1993.5
NMR data (13C, 15N, 17O) for the three ring atoms of various oxaziridines are compared. Their significance for the prediction of the enantioselectivity of the oxidation of sulphides by chiral oxaziridines is discussed.