- Straightforward access to cyclic amines by dinitriles reduction
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1,1,3,3-Tetramethyldisiloxane (TMDS) and polymethylhydrosiloxane (PMHS), when associated with titanium(IV) isopropoxide, provide two convenient systems for the reduction of nitriles into the corresponding primary amines. Kinetics of the two systems have been studied by 1H NMR and demonstrated that reduction with PMHS occurs faster than with TMDS. These two titanium-based systems reduce both aromatic and aliphatic nitriles in the presence of Br, CC, NO2, OH, and cyclopropyl-ring. In the case of cyclopropyl-nitriles, the formation of secondary amines, which come from an intermolecular reductive alkylation reaction was observed. This result was exploited for the reduction of dinitriles, which led, in one-step, to azepane, piperidine, pyrrolidine, and azetidine derivatives through an intramolecular reductive alkylation reaction.
- Laval, Stéphane,Dayoub, Wissam,Pehlivan, Leyla,Métay, Estelle,Favre-Reguillon, Alain,Delbrayelle, Dominique,Mignani, Gérard,Lemaire, Marc
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supporting information
p. 975 - 983
(2014/01/23)
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- METHODS OF MAKING CYCLIC, N-AMINO FUNCTIONAL TRIAMINES
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The present invention provides strategies for making cyclic triamines. Reactant media including certain precursors and/or certain types of catalysts can be converted into cyclic triamines with improved conversion and selectivity. The strategies can be incorporated into reactions that involve transamination schemes and/or reductive amination schemes. In the case of transamination, for instance, using transamination to cause ring closure of higher amines in the presence of a suitable catalyst leads to desired cyclic triamines with notable conversion and yield. In the case of reductive amination, reacting suitable polyfunctional precursors in the presence of a suitable catalyst also yields cyclic triamines via ring closure with notable selectivity and conversion. Both transamination and reductive amination methodologies can be practiced under much milder temperatures than are used when solely acid catalysts are used. Preferred embodiments can produce reaction mixtures that are generally free of salt by-products.
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Page/Page column 30-31
(2010/04/28)
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- Synthesis and properties of oligo-2′-deoxyribonucleotides containing internucleotidic phosphoramidate linkages modified with pendant groups ending with either two amino or two hydroxyl functions
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Single and multiple incorporations of stereochemically pure modified dinucleoside-phosphoramidates involving substituent groups ending with bis-hydroxyethyl and bis-aminoethyl groups have been performed into pyrimidic triple helix-forming oligo-2′-deoxyribonucleotides designed to bind parallel to the purine strand of the DNA target. The ability of these modified oligo-2′-deoxyribonucleotides to form triple helices has been studied by UV-melting curve analyses, and circular dichroism. Only the oligonucleotides involving modified phosphate groups with the Rp configuration formed more stable triple helices than did the parent phosphodiester sequences. Incorporating the modifications into the third oligonucleotide strands has little effect on the structure of the triplexes. At pH 7, the incorporation of two, three or four modified phosphate groups into the third strands stabilizes the triplexes, as compared to the unmodified oligonucleotide. Stronger stabilization was observed with compounds containing linkers ending with amino functions. Stability increases with the number of modifications without being fully additive. This might be due to the different environments of the phosphate groups inside the sequence.
- Asseline, Ulysse,Chassignol, Marcel,Draus, Jolanta,Durand, Maurice,Maurizot, Jean-Claude
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p. 3499 - 3511
(2007/10/03)
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- Synthesis and DNA-Sequence Selectivity of a Series of Mono- and Difunctional 9-Aminoacridine Nitrogen Mustards
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The aim of this work was to identify nitrogen mustards that would react selectively with DNA, particularly in G-rich regions.A series of mono- and difunctional nitrogen mustards was synthesized in which the (2-chloroethyl)amino functions were connected to the N9 of 9-aminoacridine by way of a spacer chain consisting of two to six methylene units.The length of the spacer chain connecting the alkylating and putative DNA-intercalating groups was found to affect the preference for the alkylation of different guanine-N7 positions in a DNA sequence.All of the compounds reacted preferentially at G's that are followed by G as do most other types of nitrogen mustards, but the degree of selectivity was greater.The compounds reacted at much lower concentrations than were required for comparable reaction by mechlorethamine (HN2), consistent with initial noncovalent binding to DNA prior to guanine-N7 alkylation.The degree of DNA-sequance selectivity increased as the spacer-chain length decrease below four methylene units.Most strikingly, long spacer compounds reacted strongly at 5'-GT-3' sequences, whereas this reaction was almost completely suppressed when the spacer length was reduced to two or three methylenes.Mono- and difunctional compounds of a given spacer length showed no consistent difference in DNA-sequence preference.
- Kohn, Kurt W.,Orr, Ann,O'Connor, Patrick M.,Guziec, Lynn James,Guziec, Frank S.
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- Process for preparing nitrogen-containing heterocyclic compounds
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Nitrogen-containing heterocyclic compounds are prepared by cyclization of a compound having the formula: EQU1 or EQU2 wherein X represents a hydrogen atom or --CH2 CHR-Y; R represents a hydrogen atom or methyl atom; Y represents an --OH group or --NH2 group; and n represents the integers 0 or 1 - 4; with a zeolite catalyst having the formula wherein M represents a cation selected from alkali metals, alkaline earth metals, zinc group elements, hydrogen and ammonium cations; n represents the valence of the cation; a is 1.0 ± 0.5 and m is 2 - 12.
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