Ammonium Formate in Organic Synthesis: A Versatile Agent in Catalytic Hydrogen Transfer Reductions

Ram, Siya; Ehrenkaufer, Richard E.

doi:10.1055/s-1988-27478

Cited by 227 publications

(87 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Further, the magnesium-mediated reduction of aromatic nitro compounds, [16] Barbier reaction [17] and in situ Grignard reactions [18] has also been demonstrated. The application of ammonium formate [19,20] in the field of catalytic transfer hydrogenation for the reduction of variety of organic compounds and in the synthesis of peptides is peer reviewed.…”

Section: Reprintsmentioning

confidence: 99%

Magnesium‐Catalyzed Proficient Reduction of Oximes to Amines Using Ammonium Formate

Abiraj

Gowda

2004

Synthetic Communications

View full text Add to dashboard Cite

Section: Reprintsmentioning

confidence: 99%

Magnesium‐Catalyzed Proficient Reduction of Oximes to Amines Using Ammonium Formate

Abiraj

Gowda

2004

Synthetic Communications

View full text Add to dashboard Cite

“…The reduction of carbonyl compounds to amines with formic acid or formamide is known as the Leuckart-Wallach reaction. [5] Few studies on the use of catalysts in this reaction have been reported in the literature.…”

mentioning

confidence: 99%

Highly Enantioselective Hydrogen‐Transfer Reductive Amination: Catalytic Asymmetric Synthesis of Primary Amines

Kadyrov¹,

Riermeier²

2003

Angew Chem Int Ed

267

View full text Add to dashboard Cite

Optically active amines are attracting increasing interest in the food, agrochemical, and pharmaceutical industries as building blocks for novel compounds and as templates for asymmetric synthesis. One of the most common methods for preparing amines is the reductive amination of carbonyl compounds.[1] We have successfully explored the rhodiumcatalyzed asymmetric reductive amination with hydrogen as the reducing agent.[2] Recently, we developed a highly active and enantioselective catalytic system for the reductive amination of a-keto acids.[3] In the course of our studies we observed that the reaction of phenylpyruvic acid in methanolic ammonia at 60 8C in the presence of a Rh catalyst smoothly furnished N-(phenylacetyl)phenylalaninamide [Eq. (1)]. The formation of this product from phenylpyruvic acid and ammonium sulfate proceeds in the absence of a catalyst at a higher temperature (105 8C). [4] This observation prompted us to investigate a reductive amination mediated by chiral catalysts under hydrogentransfer conditions. The reduction of carbonyl compounds to amines with formic acid or formamide is known as the Leuckart-Wallach reaction.[5] Few studies on the use of catalysts in this reaction have been reported in the literature.[6] As part of our ongoing research into the asymmetric hydrogen-transfer reductive amination, [7] we report herein our results from the screening of a variety of catalyst types and describe an effective catalytic system for the production of simple amines with high enantioselectivity.Two conventional hydrogen sources, isopropyl alcohol and formic acid, [8] were considered. In the reductive amination of acetophenone with ammonia in isopropyl alcohol only [Rh(C 5 Me 5 )Cl 2 ] 2 demonstrated acceptable activity. In the presence of this catalyst, 1-phenylethylamine (1) and 1-phenylethanol (2) were produced in 12 h at 70 8C in yields of 30 % and 1 %, respectively. Figure 1 shows the yields determined by GC of 1 and 2 and the enantiomeric excess of 1 in the reaction of acetophenone with ammonium formate for the different Rh, Ir, and Ru complexes that were tested as catalysts. The use of Rh and Ir complexes resulted in poor enantioselectivities under all conditions investigated. Therefore, we concentrated on Ru systems with ammonium formate as the hydrogen donor (Leuckart-Wallach-type reductive amination).As can be seen in Figure 1, the best enantioselectivities were observed with Ru catalysts with a binap or a tol-binap ligand. The degree of asymmetric induction by both catalysts was evaluated for a number of aryl ketones. The reactions were quenched after 24 h, and the crude reaction mixtures were analyzed directly by HPLC for the ee values of the products. The results indicate that the Ru-tol-binap complex gives higher enantioselectivities than the Ru-binap complex ( Table 1). As a result of the very broad peaks observed with our fast method of HPLC analysis, we were unable to detect another enantiomer in the reactions represented in entries 2, 3, and 5 of Table 1.Optimization of the reac...

show abstract

“…It is well known in organic chemistry that the azide moiety is a good leaving group and that its conversion into an amino group is feasible (20). Chemical reduction of alkyl azides into amine derivates have been demonstrated by the use of ammonium formate (10,20), which is used in the chromatographic conditions for the direct determination of nucleotides by (21).…”

Section: Discussionmentioning

confidence: 99%

“…Chemical reduction of alkyl azides into amine derivates have been demonstrated by the use of ammonium formate (10,20), which is used in the chromatographic conditions for the direct determination of nucleotides by (21). However, the conditions for this transformation used concentrations of the reducing agents (glutathione at 200 mM) higher than those present in the cells (glutathione cytoplasm concentration, 20 mM) (11).…”

Section: Discussionmentioning

confidence: 99%

Lack of Evidence for In Vivo Transformation of Zidovudine Triphosphate to Stavudine Triphosphate in Human Immunodeficiency Virus-Infected Patients

Meléndez

Blanco

Delgado

et al. 2006

Antimicrob Agents Chemother

View full text Add to dashboard Cite

The in vivo and in vitro determination of significant intracellular stavudine (d4T) triphosphate (d4TTP) concentrations in human immunodeficiency virus (HIV)-infected subjects and NS-1 cells treated with zidovudine (ZDV) has recently been reported. This study was conducted to corroborate these findings with in vivo samples from HIV-infected subjects taking ZDV and in vitro CEM SS cells incubated with different ZDV concentrations. Previously, we have reported on our validated high-performance liquid chromatography coupled with tandem mass spectrometry methodology for the simultaneous determination of d4TTP, lamivudine triphosphate, and ZDV triphosphate (ZDVTP) concentrations. Using this methodology, we monitored the d4TTP concentration in more than 100 samples from HIV-infected subjects treated with d4T. In addition, we simultaneously monitored the concentrations of d4TTP and ZDVTP in more than 500 samples from HIVinfected individuals who were taking ZDV. Finally, we performed in vitro studies by incubating CEM SS cells with 10 M, 50 M, and 100 M ZDV and monitored the formation of d4TTP at 24 and 48 h. We could measure d4TTP concentrations from HIV-infected individuals with a limit of quantitation (LOQ) of 2.7 fmol/10 6 cells (total injection, 54 fmol). In the in vivo studies, we measured the d4TTP concentrations among patients receiving d4T treatment, but the samples from patients taking ZDV did not provide d4TTP concentrations above the LOQ. Furthermore, in vitro samples did not produce any signal for d4TTP, despite the detection of substantial ZDVTP concentrations in CEM SS cells. Thus, contrary to the previous report, we found no evidence for the in vivo or in vitro transformation of ZDVTP to d4TTP in HIV-infected subjects or CEM SS cells.Nucleoside reverse transcriptase inhibitors are an essential part of the highly active antiretroviral therapy implemented for the treatment of human immunodeficiency virus (HIV)-infected individuals (24). Two of the most widely used nucleoside reverse transcriptase inhibitors are zidovudine (ZDV) (8) and stavudine (d4T) (7). ZDV and d4T are thymidine nucleoside analogs that need to be converted into their active forms, zidovudine triphosphate (ZDVTP) and stavudine triphosphate (d4TTP), to be effective against HIV replication (6, 14). Furthermore, it has been established that ZDV and d4T use the same intracellular mechanisms for their activation processes (6, 14), and combination therapy with these two analogs is not recommended (12,15,16).Various methods (indirect and direct detection of nucleotides) have been developed for the determination of intracellular ZDVTP and d4TTP in vivo. The indirect methodologies fractionate the phosphate anabolites (ZDV monophosphate, ZDV diphosphate, ZDVTP, d4T monophosphate, d4T diphosphate, and d4TTP) by the use of ion-exchange cartridges or ionic liquid chromatography, followed by dephosphorylation and quantification of the parent drug (ZDV and d4T) by radioimmunoassays or by high-performance liquid chromatography coupled with tandem mass s...

show abstract

Ammonium Formate in Organic Synthesis: A Versatile Agent in Catalytic Hydrogen Transfer Reductions

Cited by 227 publications

References 0 publications

Magnesium‐Catalyzed Proficient Reduction of Oximes to Amines Using Ammonium Formate

Magnesium‐Catalyzed Proficient Reduction of Oximes to Amines Using Ammonium Formate

Highly Enantioselective Hydrogen‐Transfer Reductive Amination: Catalytic Asymmetric Synthesis of Primary Amines

Lack of Evidence for In Vivo Transformation of Zidovudine Triphosphate to Stavudine Triphosphate in Human Immunodeficiency Virus-Infected Patients

Contact Info

Product

Resources

About