scholarly journals Binuclear metal carbonyl DAB complexes. III. Activation of a CN double bond in Ru2(CO)6(DAB) complexes (DAB = 1, 4-diazabutadiene). C C bond formation between two DAB ligands

1979 ◽  
Vol 37 ◽  
pp. L485-L487 ◽  
Author(s):  
L.H. Staal ◽  
L.H. Polm ◽  
G. Van Koten ◽  
K. Vrieze
ChemInform ◽  
1988 ◽  
Vol 19 (2) ◽  
Author(s):  
Z. HOU ◽  
Y. FUJIWARA ◽  
T. JINTOKU ◽  
N. MINE ◽  
K. YOKOO ◽  
...  
Keyword(s):  

2021 ◽  
Vol 18 ◽  
Author(s):  
Azizuddin ◽  
Muhammad Iqbal ◽  
Syed Ghulam Musharraf

: For several decades, biotransformational studies on steroidal compounds have gained a lot of attention because it is an efficient approach for the structural modification of complicated natural or synthetic compounds with high regio-, chemo- and stereoselectivity at environmentally friendly conditions. This review summarizes the use of different strains of Cunninghamella blakesleeana for the biotransformation of sixteen steroids 1-16 into a variety of transformed products. The transformed products may be important as a drug or precursor for the production of important pharmaceuticals. The types of reactions performed by C. blakesleeana include hydroxylation, epoxidation, reduction, demethylation, oxidation, glycosidation, double bond formation, side-chain degradation, isomerisation and opening of an isoxazol ring, which would be difficult to produce by traditional synthesis.


2015 ◽  
Vol 11 ◽  
pp. 1163-1174 ◽  
Author(s):  
Michael Weßling ◽  
Hans J Schäfer

Nitroalkenes are easily accessible in high variety by condensation of aldehydes with aliphatic nitroalkanes. They belong to the group of activated alkenes that can be hydrodimerized by cathodic reduction. There are many olefins with different electron withdrawing groups used for cathodic hydrodimerization, but not much is known about the behaviour of the nitro group. Synthetic applications of this group could profit from the easy access to nitroolefins in large variety, the C–C bond formation with the introduction of two nitro groups in a 1,4-distance and the conversions of the nitro group by reduction to oximes and amines, the conversion into aldehydes and ketones via the Nef reaction and base catalyzed condensations at the acidic CH bond. Eight 1-aryl-2-nitro-1-propenes have been electrolyzed in an undivided electrolysis cell to afford 2,5-dinitro-3,4-diaryl hexanes in high yield. The 4-methoxy-, 4-trifluoromethyl-, 2-chloro- and 2,6-difluorophenyl group and furthermore the 2-furyl and 2-pyrrolyl group have been applied. The reaction is chemoselective as only the double bond but not the nitro group undergoes reaction, is regioselective as a ß,ß-coupling with regard to the nitro group and forms preferentially two out of six possible diastereomers as major products.


1986 ◽  
Vol 41 (5) ◽  
pp. 629-639 ◽  
Author(s):  
Anna-Margarete Hinke ◽  
Axel Hinke ◽  
Wilhelm Kuchen ◽  
Wolfgang Hönle

Abstract Reduction of MentPBr2M(CO)5 1 (M = Cr, W) with magnesium in THF yields the diphos­phene complex (CO)5M(Ment)P=P(Ment)M(CO)5 2 as the main product. In addition, a phosphinidene complex, (CO)5M(Ment)PM(CO)5 (3) is also formed. The latter is obtained in larger amounts, if the reaction is carried out in the presence of M(CO)5THF. The proposed structures are confirmed by NMR and UV data as well as - in the case of the chromium compounds (2a, 3a) - by crystal structure analysis. Compound 2a is obtained only as the frans-isomer. The P-P distance in 2a (204.0 pm) indicates a double bond which does not participate in the complex formation. The P-Cr distance in 3a (average: 230.3 pm) is within the low est range found for this element combination. Reaction of 2a with LiAlH4 yields the diphosphane complex (CO)5CrMent(H)P-P(H)MentCr(CO)5 4 as a mixture of “meso” and “rac” diastereomers.


2010 ◽  
Vol 51 (14) ◽  
pp. 1822-1825 ◽  
Author(s):  
Thomas A. Ramirez ◽  
Baoguo Zhao ◽  
Yian Shi
Keyword(s):  

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