163629-15-0Relevant articles and documents
Direct N-Alkylation/Fluoroalkylation of Amines Using Carboxylic Acids via Transition-Metal-Free Catalysis
Lu, Chunlei,Qiu, Zetian,Xuan, Maojie,Huang, Yan,Lou, Yongjia,Zhu, Yiling,Shen, Hao,Lin, Bo-Lin
supporting information, p. 4151 - 4158 (2020/08/21)
A scalable protocol of direct N-mono/di-alkyl/fluoroalkylation of primary/secondary amines has been constructed with various carboxylic acids as coupling agents under the catalysis of a simple air-tolerant inorganic salt, K3PO4. Advantageous features include 100 examples, 10 drugs and drug-like amines, fluorinated complex tertiary amines, gram-scale synthesis and isotope-labelling amine, thus demonstrating the potential applicability in industry of this methodology. The involvement of relatively less reactive silicon-hydride compared with the traditional reactive metal-hydride or boron-hydride species required to reduce the amide intermediates presumably contributes to the remarkable functional group compatibility. (Figure presented.).
Selective N-alkylation of amines using nitriles under hydrogenation conditions: Facile synthesis of secondary and tertiary amines
Ikawa, Takashi,Fujita, Yuki,Mizusaki, Tomoteru,Betsuin, Sae,Takamatsu, Haruki,Maegawa, Tomohiro,Monguchi, Yasunari,Sajiki, Hironao
supporting information; experimental part, p. 293 - 304 (2012/02/01)
Nitriles were found to be highly effective alkylating reagents for the selective N-alkylation of amines under catalytic hydrogenation conditions. For the aromatic primary amines, the corresponding secondary amines were selectively obtained under Pd/C-catalyzed hydrogenation conditions. Although the use of electron poor aromatic amines or bulky nitriles showed a lower reactivity toward the reductive alkylation, the addition of NH4OAc enhanced the reactivity to give secondary aromatic amines in good to excellent yields. Under the same reaction conditions, aromatic nitro compounds instead of the aromatic primary amines could be directly transformed into secondary amines via a domino reaction involving the one-pot hydrogenation of the nitro group and the reductive alkylation of the amines. While aliphatic amines were effectively converted to the corresponding tertiary amines under Pd/C-catalyzed conditions, Rh/C was a highly effective catalyst for the N-monoalkylation of aliphatic primary amines without over-alkylation to the tertiary amines. Furthermore, the combination of the Rh/C-catalyzed N-monoalkylation of the aliphatic primary amines and additional Pd/C-catalyzed alkylation of the resulting secondary aliphatic amines could selectively prepare aliphatic tertiary amines possessing three different alkyl groups. According to the mechanistic studies, it seems reasonable to conclude that nitriles were reduced to aldimines before the nucleophilic attack of the amine during the first step of the reaction.
Synthesis and dihydrofolate reductase inhibitory activities of 2,4- diamino-5-deaza and 2,4-diamino-5,10-dideaza lipophilic antifolates
Gangjee,Devraj,Queener
, p. 470 - 478 (2007/10/03)
Two series of nonclassical antifolates (2,4-diamino-5-deaza compounds 2- 5 and 5,10-dideaza compounds 6-13) were synthesized as inhibitors of dihydrofolate reductase (DHFR) from Pneumocystis carinii (pc) and Toxoplasma gondii (tg) organisms that are responsible for fatal opportunistic infections in AIDS patients. Rat liver (rl) DHFR served as the mammalian reference enzyme to determine selectivity. Syntheses of the target 5-deaza compounds were achieved by initial construction of the pivaloyl-protected 2,4-diamino- 6-bromopyrido[2,3-d]-pyrimidine 17 via a cyclocondensation of 2,4,6- triaminopyrimidine with bromomalonaldehyde. Sequential Heck coupling of 17 with styrene followed by ozonolysis afforded the 6-formyl derivative 19. Reductive amination of 19 with 3,4,5-trimethoxyaniline afforded the N10-H analog. The N10-Me and N10-Et analogs were synthesized by nucleophilic displacement of the 6-bromomethyl derivative 22 (obtained from the 6-formyl derivative 19 by reduction and bromination) with the appropriate N- alkylaniline. The trans-5,10-dideaza analogs 6-8 were synthesized via a Heck coupling of the appropriate methoxystyrene with 17, and selective reduction of the resulting 9,10-double bond afforded target compounds 9-11. Further reduction to the tetrahydro derivatives afforded analogs 12 and 13. The 5- deaza N10-Me 3,4,5-trimethoxy analog 3 maintained the best balance of potency and selectivity against both tgDHFR and pcDHFR. Compared to trimethoprim, compound 3 was only slightly less selective but was 300-fold more potent against tgDHFR. The 5,10-dideaza analogs were generally less potent and selective than the 5-deaza compounds.
