133437-08-8Relevant articles and documents
Sequential hydroaminomethylation/Pd-catalyzed hydrogenolysis as an atom efficient route to valuable primary and secondary amines
October, Jacquin,Mapolie, Selwyn F.
supporting information, (2021/04/12)
The facile synthesis of valuable primary and secondary amines is reported using a sequential procedure of hydroaminomethylation and Pd-catalyzed hydrogenolysis. The hydroaminomethylation reaction was catalyzed by a cationic Rh(I) iminopyridyl complex and the N-alkylated benzylamines were produced with high chemoselectivity, albeit as mixtures of linear and branched products. Performing the hydrogenolysis reaction using 10% Pd/C, provided access to valuable primary and secondary amines which have applications in the surfactant, pharmaceutical and polymer industries.
METHOD FOR PREPARING 6-AMINOHEXYL LACTOSIDE-NOTA CONJUGATE
-
, (2017/07/14)
The present invention provides a method for preparing a 6-aminohexyl lactoside-NOTA conjugate. The preparation method comprises brominating perbenzoylated lactose with hydrobromic acid; glycosylating 6-azidohexanol to obtain 6-azidohexyl perbenzoyl lactoside; and deprotecting this precursor in two steps to obtain 6-aminohexyl lactoside and conjugating 6-aminohexyl lactoside to NCS-benzyl-NODA GA (i.e. 2,2′-(7-(1-carboxy-4-((4-isothiocyanate benzyl) amino)-4-oxobutyl)-1,4,7-triazonane-1,4-diyl) diacetic acid) in triethyl amine as an alkaline solvent, to obtain a 6-aminohexyl lactoside-NCS-benzyl-NODA GA conjugate. In this novel preparation method, no deglycosylated side product is produced, such that the yield is considerably increased to 46%. Therefore, the method is suitable for future massive production since the requirement for repeated preparations for massive production is reduced, and the impurities produced in the previously scaled-up preparation process are not present.
Acid promoted cyclodehydration of amino alcohols with amide acetal
Hwang, Soonho,Park, Heemin,Kwon, Yongseok,Kim, Sanghee
, p. 60017 - 60024 (2015/02/19)
A convenient acid-promoted cyclization protocol for the formation of azaheterocycles from amino alcohols is described. The reaction involves the use of N,N-dimethylacetamide dimethyl acetal (DMADA) as the activating reagent of the hydroxyl group. Using this protocol, pyrrolidines or piperidines with various substituents can be synthesized in good to high yields.
Rate enhancement of the catechol oxidase activity of a series of biomimetic monocopper(ii) complexes by introduction of non-coordinating groups in N-tripodal ligands
Marion, Ronan,Saleh, Nidal M.,Le Poul, Nicolas,Floner, Didier,Lavastre, Olivier,Geneste, Florence
, p. 1828 - 1835 (2012/10/08)
Asymmetrical N-tripodal ligands have been synthesized in three steps. Diversity has been introduced at the first step of the synthesis by adding pyrazine, pyridine, benzyl and thiophene rings. The corresponding Cu II complexes have been prepared by reaction with CuCl2 and characterized by Electron Paramagnetic Resonance (EPR), UV-Vis spectroscopies and cyclic voltammetry. The data show that the ligand coordinates to Cu II in a mononuclear fashion in solution and that the complexes display a square pyramidal geometry. All complexes are characterized by a quasi-reversible one-electron redox behavior in acetonitrile. The ability of the complexes to oxidize 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone has been studied and the results show that the rate of the reaction depends on the basicity and the steric hindrance of the heterocyclic donor. Best results have been obtained with CuII complexes coordinated to bidentate ligands, since they facilitate the approach and the coordination of catechol to the metal. Particularly, the introduction of a thiophenyl group to mimic the sulfur atom at proximity to the catalytic center in the catechol oxidase protein structure improves the catalytic activity of the complex.
A mild, palladium-catalyzed method for the dehydrohalogenation of alkyl bromides: Synthetic and mechanistic studies
Bissember, Alex C.,Levina, Anna,Fu, Gregory C.
, p. 14232 - 14237 (2012/11/06)
We have exploited a typically undesired elementary step in cross-coupling reactions, β-hydride elimination, to accomplish palladium-catalyzed dehydrohalogenations of alkyl bromides to form terminal olefins. We have applied this method, which proceeds in excellent yield at room temperature in the presence of a variety of functional groups, to a formal total synthesis of (R)-mevalonolactone. Our mechanistic studies have established that the rate-determining step can vary with the structure of the alkyl bromide and, most significantly, that L2PdHBr (L = phosphine), an intermediate that is often invoked in palladium-catalyzed processes such as the Heck reaction, is not an intermediate in the active catalytic cycle.
Reductive hydroxyalkylation/alkylation of amines with lactones/esters
Wang, Yu-Huang,Ye, Jian-Liang,Wang, Ai-E,Huang, Pei-Qiang
, p. 6504 - 6511 (2012/09/08)
We have developed a one-pot method for the direct intermolecular reductive hydroxyalkylation or alkylation of amines using lactones or esters as the hydroxyalkylating/alkylating reagents. The method is based on the in situ amidation of lactones/esters with DIBAL-H-amine complex (for primary amines) or DIBAL-H-amine hydrochloride salt complex (for secondary amines), followed by reduction of the amides with an excess of DIBAL-H. Different from the reduction of Weinreb amides with DIBAL-H where aldehydes are formed, the reduction of the in situ formed Weinreb amides yielded amines. Moreover, this method is not limited to Weinreb amides, instead, it also works for other amides in general. A plausible mechanism is suggested to account for the outcome of the reactions.
Hydroboration with pyridine borane at room temperature
Clay, Julia M.,Vedejs, Edwin
, p. 5766 - 5767 (2007/10/03)
Treatment of pyridine borane (Py·BH3) with iodine, bromine, or strong acids affords activated Py·BH2X complexes that are capable of hydroborating alkenes at room temperature. Evidence is presented for an unusual hydroboration mechanism involving leaving group displacement. In contrast to THF·BH3, hydroboration with Py·BH2I selectively affords the monoadducts. The crude hydroboration products are converted into synthetically useful potassium alkyltrifluoroborate salts upon treatment with methanolic KHF2. Copyright
Utilization of lithium triethylborohydride as a selective N-acyl deprotecting agent
Tanaka, Hideyuki,Ogasawara, Kunio
, p. 4417 - 4420 (2007/10/03)
Lithium triethylborohydride has been found to be a superior and selective reagent for the removal of tertiary N-acyl protecting groups. The reagent selectively removes tertiary amide acyl functionality without affecting secondary amide functionality even when they are present in the same molecule. Some tertiary carbamates may be also removed under the same conditions.
Pyrimidinone-1,3-oxathiolane derivatives with antiviral activity
-
, (2008/06/13)
Compounds of formula (I) wherein Ra and Rb the same or different, are hydrogen atoms, acyl groups deriving from a lower carboxylic acid or chains of formula (a) useful as reverse transcriptase inhibitors antiviral activity are described.
Synthesis and anti-HIV evaluation of new 2',3'-dideoxy-3'-thiacytidine prodrugs
Mourier, Nicolas,Camplo, Michel,Della Bruna, Giovanna Schioppacassi,Pellacini, Francesco,Ungheri, Domenico,Chermann, Jean-Claude,Kraus, Jean-Louis
, p. 1057 - 1091 (2007/10/03)
A series of anti-HIV prodrugs possessing various polyaminated side arms have been developed. The incorporation of a N-Boc protected monoamine or diamine side arm into the backbone of the 2',3'-dideoxy-3'-thiacytidine 1 (BCH-189) provided an increase in antiviral potency, which could be several orders magnitude greater than the parent drug (1) depending on the cell culture systems used (MT-4 or MDMs). Twenty six 2',3'-dideoxy-3'-thiacytidine prodrugs which differ from each other by the length, the nature of the 5'-O function and the 5'-O or/and N-4 position on the nucleoside moiety were synthesized. Among this new series of prodrugs, several congeners (12c and 12a) were found to inhibit HIV-1 replication in cell culture with 50% effective concentrations EC50 of 10 and 50 nM respectively, in MT-4 cells. Compound 12c was found more active on infected MDMs cells with 50% effective concentration of 0.01 nM. The synthesis and the antiviral properties of these compounds are discussed.