Search results for "pane"
showing 10 items of 1074 documents
CCDC 984093: Experimental Crystal Structure Determination
2014
Related Article: Pallab Bhowmik, Saptarshi Biswas, Shouvik Chattopadhyay, Carmen Diaz, Carlos J. Gómez-García, Ashutosh Ghosh|2014|Dalton Trans.|43|12414|doi:10.1039/C4DT00328D
CCDC 1955601: Experimental Crystal Structure Determination
2020
Related Article: Lucia Volbach, Niklas Struch, Fabian Bohle, Filip Topić, Gregor Schnakenburg, Andreas Schneider, Kari Rissanen, Stefan Grimme, Arne Lützen|2020|Chem.-Eur.J.|26|3335|doi:10.1002/chem.201905070
CCDC 1449686: Experimental Crystal Structure Determination
2016
Related Article: Kaisa Helttunen, Maija Nissinen|2016|CrystEngComm|18|4944|doi:10.1039/C6CE00243A
CCDC 1547125: Experimental Crystal Structure Determination
2017
Related Article: Alokesh Hazari, Carlos J. Gómez-García, Michael G.B. Drew, Ashutosh Ghosh|2017|Polyhedron|138|145|doi:10.1016/j.poly.2017.09.012
Functionalized Dialdehydes as Promising Scaffolds for Access to Heterocycles and β-Amino Acids: Synthesis of Fluorinated Piperidine and Azepane Deriv…
2017
Functionalized dialdehydes are considered important substrates that can be transformed into various substituted heterocyclic, alicyclic, and polysubstituted compounds. Here, we report a robust stereocontrolled procedure for the synthesis of novel functionalized trifluoromethyl-containing piperidine and azepane derivatives, based on oxidative ring cleavage of the C=C bond of diversely substituted cycloalkenes, followed by reductive ring closure of the diformyl intermediates in the presence of fluorine-containing amines.
Diversity-Oriented Stereocontrolled Synthesis of Some Piperidine- and Azepane-Based Fluorine-Containing β-Amino Acid Derivatives
2020
AbstractStructural diversity-oriented synthesis of some azaheterocyclic β-amino acid derivatives has been accomplished by selective functionalization of readily available cyclodienes. The stereocontrolled synthetic concept was based on the oxidative ring cleavage of unsaturated cyclic β-amino acids derived from cycloalkadiene, followed by ring closing with double reductive amination, which furnished some conformationally restricted β-amino acid derivatives with a piperidine or azepane core.
Rigid biobased polycarbonates with good processability based on a spirocyclic diol derived from citric acid
2020
Introducing biobased polymers from renewable sources for use as high-performance thermoplastics with high demands on mechanical rigidity, transparency, thermal stability, as well as good processability, is a significant challenge. In the present work we have designed and prepared a rigid biobased bis-spirocylic diol by di-cycloketalization of a bicyclic diketone (cis-bicyclo[3.3.0]octane-3,7-dione, obtained from citric acid) using trimethylolpropane. This spiro-diol monomer has two reactive primary hydroxyl groups and the synthesis from inexpensive biobased starting materials is straightforward and readily upscalable, involving no chromatographic purification. In order to explore the useful…
Synthesis of fluorinated piperidine and azepane β-amino acid derivatives
2016
Abstract A convenient and robust stereocontrolled procedure has been developed for the synthesis of novel trifluoromethyl-containing piperidine and azepane β-amino ester stereoisomers. The synthesis started from readily available unsaturated bicyclic β-lactams and was based on oxidative cleavage of the ring C C double bond followed by ring closure of the diformyl intermediates in the presence of 2,2,2-trifluoroethylamine hydrochloride through reductive amination. The synthetic procedure has efficiently been extended towards the synthesis of mono- and difluorinated analogs.
Non-classical CH⋯O hydrogen-bond determining the regio- and stereoselectivity in the [3 + 2] cycloaddition reaction of (Z)-C-phenyl-N-methylnitrone w…
2015
The role of the ester groups in the regio- and stereoselectivities of the zw-type [3 + 2] cycloaddition (32CA) reaction of C-phenyl-N-methylnitrone with dimethyl 2-benzylidenecyclopropane-1,1-dicarboxylate (BCPC) has been studied using DFT methods at the MPWB1K/6-31G(d) level. The possible ortho/meta regioisomeric channels and the endo/exo stereoselective approach modes were explored and characterized. Analysis of the relative energies associated with the different reaction pathways indicates that the presence of the two CO2Me groups in the cyclopropane ring has a remarkable effect on selectivities favouring the ortho/endo path, in good agreement with the experimental data. Inclusion of sol…
A unified synthetic approach to trachylobane-, beyerane-, atisane- and kaurane-type diterpenes
2006
A general synthetic approach to the polycyclic carbon skeleton of biogenetically related trachylobane, beyerane, atisane, and kaurane diterpenes from carvone is described. The skeleton of these diterpenes is prepared from a common intermediate, that is, 25, readily prepared from carvone using an IMDA reaction and an intramolecular diazo ketone cyclopropanation of an unsaturated ketone as key steps. The tetracyclic diterpene ring systems are obtained from this key trachylobane-type intermediate through the regioselective reductive cleavage of the cyclopropane ring, after adequate modification of the functionalization around the tricyclo[3.2.1.02,7]octane moiety.