Regioselective Formation of Novel Functionalized 1-Aza-9-oxafluorenes
摘要:
A small series of novel 1-aza-9-oxafluorenes have been prepared by regioselective cycloaddition reaction of p-benzoquinone to the sterically unhindered side of unsymmetrically substituted N-acyl-l,4-dihydropyridines (1). The stereochemistry of the products is discussed on the basis of X-Ray crystal structure analysis of one starting structure (la). The formation of pyridine derivatives by possible redox reaction of the adducts was not observed. Rotameric properties of the N-acyl-1,4-dihydropyridines are demonstrated by H-1 and C-13 NMR spectroscopy, thus stabilizing the 1,4-dihydropyridine system towards competing oxidation by the quinone.
Synthesis and first biological evaluation of 1-aza-9-oxafluorenes as novel lead structures for the development of small-sized cytostatics
摘要:
A first series of novel 1-aza-9-oxafluorenes has been prepared from 3-carbonyl substituted 1,4-dihydropyridines and p-benzoquinone as small-sized cytostatics. Biological evaluation has been carried out in various cancer cell-lines. First structure-activity relationships proved the 4-phenyl substituent to be more favorable than the 4-methyl substituent. Cytostatic properties are discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.
The first series of synthetic 1-aza-9-oxafluorenes with cytostatic activities in the micromolar range was evaluated as cyclin-dependent kinase (CDK1) inhibitors. Activity was found to be selective in comparison to the inhibition of other kinases within the CDK family. Compounds were shown to inhibit the membrane-efflux pump P-glycoprotein responsible for multidrug resistance in cancer cells. First structure-activity relationships are discussed.
Regioselective Formation of Novel Functionalized 1-Aza-9-oxafluorenes
A small series of novel 1-aza-9-oxafluorenes have been prepared by regioselective cycloaddition reaction of p-benzoquinone to the sterically unhindered side of unsymmetrically substituted N-acyl-l,4-dihydropyridines (1). The stereochemistry of the products is discussed on the basis of X-Ray crystal structure analysis of one starting structure (la). The formation of pyridine derivatives by possible redox reaction of the adducts was not observed. Rotameric properties of the N-acyl-1,4-dihydropyridines are demonstrated by H-1 and C-13 NMR spectroscopy, thus stabilizing the 1,4-dihydropyridine system towards competing oxidation by the quinone.
Synthesis and first biological evaluation of 1-aza-9-oxafluorenes as novel lead structures for the development of small-sized cytostatics
作者:Kristin Brachwitz、Andreas Hilgeroth
DOI:10.1016/s0960-894x(01)00769-7
日期:2002.2
A first series of novel 1-aza-9-oxafluorenes has been prepared from 3-carbonyl substituted 1,4-dihydropyridines and p-benzoquinone as small-sized cytostatics. Biological evaluation has been carried out in various cancer cell-lines. First structure-activity relationships proved the 4-phenyl substituent to be more favorable than the 4-methyl substituent. Cytostatic properties are discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.