Reduction of quinolines to 1,2,3,4-tetrahydro derivatives employing a combination of NaCNBH3 and BF3.OEt2

Selective hydrogenation of unprotected indole to indoline over N-doped carbon supported palladium catalyst

“…The structure of indoline can be found extensively in natural 12 alkaloids with biological activity and pharmaceutical molecules 13 [1][2][3]. Indolines can be obtained by direct reduction of indoles or 14 ring closure through intermolecular amination reaction [4,5].…”

Allosteric inhibitors of hepatitis C virus NS5B polymerase thumb domain site II: Structure-based design and synthesis of new templates

“…5-Bromoquinoline-8-carboxylic acid 18 was first coupled with 3-chloroaniline, the amide was then reduced to 19a,b in the presence of sodium cyanoborohydride and BF 3 ÁEt 2 O in high yield. 19 A two step sequence furnished 20a,b. The introduction of the side chains by aromatic nucleophilic substitution gave unsatisfactory results.…”

“…1 (22). A solution of quinoxaline-5-carboxylic acid 19 21 (500 mg, 2.87 mmol) in CH 2 Cl 2 (30 mL) was treated with DIPEA (1.1 mL, 6.32 mmol), 3-chloroaniline (0.33 mL, 3.16 mmol) and HATU (1.20 g, 3.16 mmol). The reaction mixture was stirred at rt overnight.…”

5,8-Dimethoxy-2-phenyl-1,4-dihydroquinoline-3-carbonitrile

“…For our previous work on the preparation of quinoline derivatives see: Benzerka et al (2008); Ladraa et al (2009Ladraa et al ( , 2010; Moussaoui et al (2002); Menasra et al (2005); Belfaitah et al (2006); Bouraiou et al (2006Bouraiou et al ( , 2007Bouraiou et al ( , 2008. For more details of quinoline reduction, see: Dauphinee & Forrest (1978); Srikrishna et al (1996); Vierhapper & Eliel (1975); Lim et al (1995). T = 150 K 0.27 Â 0.07 Â 0.05 mm…”

“…Sodium in liquid ammonia converted quinoline to 1,2-dihydroquinoline (Dauphinee et al, 1978). 1,2,3,4-tetrahydroquinoline was obtained by catalytic hydrogenation and by reduction with borane and sodium cyanoborohydride (Srikrishna et al, 1996), 5,6,7,8-tetrhydroquinoline by catalytic hydrogenation over platinum oxide or 5% palladium or rhodium on carbon in triflouroacetic acid (Vierhapper et al, 1975). Vigorous hydrogenation gave cis and trans-decahydroquinoline.…”