Triethylammonium Formate Research Articles

A Convenient Method for the Conversion of Halides to Alcohols

Abstract The displacement of halides in unactivated primary bromides and iodides, allylic and benzylic primary and secondary bromides, and primary and secondary α-bromoketones by formate, using triethylammonium formate as the formylating agent, followed by acid or base catalyzed hydrolysis has been found to be an efficient method for the conversion of halides to alcohols.

A novel method for stereospecific generation of natural C-17 stereochemistry and either C-20 epimer in steroid side chains by palladium-catalyzed hydrogenolysis of C-17 and C-20 allylic carbonates.

The allylic alcohol, obtained by the reaction of C-17-keto steroid with isopropenyllithium, was converted to carbonate. Its hydrogenolysis with triethylammonium formate affords C-17β-isopropenyl group. Steroid side chain units were introduced by the reaction of C-20 keto steroid with (E) and (Z) alkenyl lithiums. The natural epimer at C-20 in steroid side-chains was generated stereospecifically by the palladium-catalyzed hydrogenolysis with triethylammonium formate of C-20 (Z) allylic carbonates, and the unnatural configuration was generated by the C-20 (E) allylic carbonate.

The Use of Mobile Phase Additives in the Determination of 55 (Polar) Pesticides by Column Liquid Chromatography-Thermospray-Mass Spectrometry

The effect of various additives (ammonium acetate, ammonium formate, triethyl- and tripropylammonium formate and chloroacetonitrile) on the sensitivity and selectivity in liquid chromatography-thermospray-mass spectrometry (positive and negative ion mode) is studied for a group of 55 pesticides including phenoxy and carboxylic acids, hydroxy-keto-lactones, substituted amides, triazines, (thio)carbamates, phenylureas, substituted phenols, organophosphorus compounds, thiocyanates and anilines. In the positive ion mode the base peaks correspond to [M + H] + and [M + NH 4 ] + for the majority of the test compounds. Fragmentation is observed in some isolated cases only. In the negative ion mode processes like (dissociative) electron capture and ion-molecule reactions take place. Fragment ions such as [M − H - CONCH 3 ] − for the carbamates, [M − C 3 H 6 O] − for the hydroxy-keto-lactones and [M − H] − for the chlorinated phenoxy acids are observed. Depending on the additive used, adduct ions such as [M + CH 3 COO] − , [M + HCOO] − and [M + CI] − are formed. Adducts with fragment ions are also observed quite often. The use of triethylammonium formate and tripropylammonium formate instead of ammonium formate increases the sensitivity and selectivity of the method in the NI mode, because their high proton affinity enhances deprotonation

Selective Catalytic Transformations of Alkynyl Cyclic Carbonates into either Homopropargylic or α-Allenyl Alcohols

Alkynyl cyclic carbonates 3 are selectively transformed by hydrogenolysis with triethylammonium formate catalyzed by Pd(dba)2 into homopropargylic alcohols 4 in the presence of PBu3 or into α-allenyl alcohols 5 with (1.2-diphenylphosphino)ethane or (1,3-diphenylphosphino)propane ligand.

A Palladium Way to Exocyclic Methylene by Formal Anti-thermodynamic Isomerization of an Endocyclic Double Bond to an Exo Position

Exocyclic methylene group is prepared by the palladium-catalyzed hydrogenolysis of endocyclic allylic formates. Endocyclic double bonds of allylic sulfones and allylic nitro compounds are isomerized to exo position by the palladium-catalyzed hydrogenolysis with triethylammonium formate.

Nucleosides and Nucleotides. 104. Radical and Palladium-Catalyzed Deoxygenation of the Allylic Alcohol Systems in the Sugar Moiety of Pyrimidine Nucleosides§,1

Abstract New methods for the synthesis of 2′,3′-didehydro-2′,3′-dideoxy-2′ (and 3′)-methyl-5-methyluridines and 2′,3′-dideoxy-2′ (and 3′)-methylidene pyrimidine nucleosides have been developed from the corresponding 2′ (and 3′)-deoxy-2′ (and 3′)-methylidene pyrimidine nucleosides. Treatment of a 3′-deoxy-3′-methylidene-5-methyluridine derivative 8 with 1,1′-thiocarbonyldiimidazole gave the allylic rearranged 2′,3′-didehydro-2′,3′-dideoxy-3′-[(imidazol-1-yl)carbonylthiomethyl] derivative 24. On the other hand, reaction of 8 with methyloxalyl chloride afforded 2′-O-methyloxalyl ester 25. Radical deoxygenation of both 24 and 25 gave 26 exclusively. Palladium-catalyzed reduction of 2′,5′-di-O-acetyl-3′-deoxy-3′-methylidene-5-methyluridine (32) with triethylammonium formate as a hydride donor regioselectively afforded the 2′,3′-dideoxy-3′-methylidene derivative 35 and 2′,3′-didehydro-2′,3′-dideoxy-3′-methyl derivative 34 in a ratio of 95:5 in 78% yield. These reactions were used on the corresponding 2′-deoxy-2′-methylidene derivatives. An alternative synthesis of 2′,3′-dideoxy-2′-methylidene pyrimidine nucleosides (43, 52, and 54) was achieved from the corresponding 1-(3-deoxy-β-D-thero-pentofuranosyl)pyrimidines (44 and 45). The cytotoxicity against L1210 and KB cells and inhibitory activity of the pathogenicity of HIV-1 are also described

Chemie und Stereochemie der Iridoide, XVII. Palladium-katalysierte Substitution an Hexaacetylaucubin

Chemistry and Stereochemistry of Iridoids, XVII. – Palladium-Catalysed Substitution of Hexaacetylacubin Acetoxy groups, in allylic position, can be replaced by nucleophiles in a palladium-catalysed reaction. The reaction of hexaacetylaucubin (2) with piperidine or benzylamine regioselectively gives the crystalline, N-containing iridoidglucosides 3 and 4. With the anion of diemethyl malonate, 5 was obtained along with the byproduct 7. Adding triethylammonium formate as a hydride donor, then the reaction gives 6; a reaction mechanism is discussed.

Use of triethylammonium formate to enhance sensitivity in negative‐ion liquid chromatography/thermospray‐mass spectrometry

AbstractThe major objective of this investigation was to find a thermospray buffer that would decrease ion/molecule reactions in the gas phase. This would cause solution chemistry and ion evaporation to be major parameters controlling ion production. Using triethylammonium formate, protonation by ion/molecule reaction in the gas phase was decreased as indicated by the effect of solution pH on ion production. The detection limits in the full‐scan mode for some amphoteric compounds and acids were one magnitude lower than those obtained with ammonium acetate or ammonium formate buffers. A few examples of sensitive full‐scan detection demonstrate the usefulness of this novel buffer for negative‐ion thermospray liquid chromatography/mass spectrometry.

ChemInform Abstract: Palladium‐Catalyzed Reduction of Aryl Sulfonates. Reduction versus Hydrolysis and Selectivity Control.

AbstractThe aryl sulfonates (I) are reduced with triethylammonium formate in the presence of a palladium diacetate/phosphine catalyst to form the corresponding arenes (II).

ChemInform Abstract: Hydrogenolysis of α,β‐Epoxy Ketone and Ester to Aldol in Pd(0)/HCOOH/ Et3N and H2/Pd/C Reduction Media.

AbstractVarious α,β‐epoxy ketones are treated with triethylammonium formate in the presence of a Pd(II) phosphine catalyst or directly hydrogenated to give hydroxy ketones, hydroxy epoxides, or diols.

An Efficient Preparation of 6,7-Didehydroestrogens

Abstract The title compounds are prepared in excellent yield by palladium-catalyzed reduction with triethyl ammonium formate of enol triflates of 6-oxo-estrogens.

Identification of 3,N4-propanodeoxycytidine 5'-monophosphate formed by the reaction of acrolein with deoxycytidine 5'-monophosphate

Acrolein reacts with deoxycytidine 5'-monophosphate at physiological pH to form one major adduct. A second minor adduct can be detected when a 3-fold excess of acrolein is present in the reaction mixture. The products were separated by ion-pair HPLC on two reverse-phase columns connected in series using triethylammonium formate as ion-pair reagent. The major adduct was characterized as 3-(5'-monophospho-2'-deoxyribosyl)-7,8, 9-trihydro-7-hydroxy-pyrimido [3,4-c]pyrimidin-2-one (3,N4-propanodeoxcytidine 5'-monophosphate). This mixture of diastereomers was formed by addition of C1 of acrolein to the exocyclic amino group at the 4-position of cytidine, followed by ring closure between C3 of acrolein and N3 of the heterocyclic ring. In order to address the utility of 32P postlabeling for the detection of this exocyclic adduct in acrolein-modified nucleic acids, an acrolein-deoxycytidine 3'-monophosphate reaction mixture was subjected to 32P postlabeling. 3-Dephosphorylation with nuclease P1 and the 3'-phosphatase activity of T4 polynucleotide kinase yields a nucleotide 5'-[32P] monophosphate which cochromatographs with 3,N4-propanodeoxycytidine 5'-monophosphate. These data indicate that 32P postlabeling and 3'-dephosphorylation can be used in conjunction with ion-pair HPLC for the detection and quantitation of acrolein-modified nucleotides.

ChemInform Abstract: One‐Pot Conversion of Phenols to Arenes.

AbstractThe phenols (Ia) ‐ (Ie) are reduced with triethylammonium formate in the presence of a Pd‐catalyst and fluoroalkanesulfonyl fluorides, giving the arenes (II).

ChemInform Abstract: Enantioselective Catalysis. Part 43. Enantioselective Catalytic Transfer Hydrogenation of α,β‐Unsaturated Carboxylic Acids Using Triethylammonium Formate.

AbstractThe catalytic properties of Rh complexes in the enantioselective hydrogenation of olefins and in the decomposition of formic acid to give H2 and CO2 are combined in the title reaction, i.e. the hydrogenation of (I) and (III) by procedure A) (bppm being the most efficient out of several chiral ligands tested).

Enantioselective Catalytic Transfer‐Hydrogenation of α,β‐Unsaturated Carboxylic Acids with Triethylammonium Formate

Enantioselective Catalytic Transfer‐Hydrogenation of α,β‐Unsaturated Carboxylic Acids with Triethylammonium Formate

ChemInform Abstract: Palladium‐Catalyzed Triethylammonium Formate Reduction of Aryl Triflates. A Selective Method for the Deoxygenation of Phenols.

Abstract Phenols can be selectively deoxygenated by reduction of the corresponding aryl triflates with triethylammonium formate in the presence of a homogeneous palladium catalyst.

Palladium catalyzed reduction of aryl triflates - utilization in thesynthesis of angelicin, olivin and chromomycinone from phenolsproduced in the benzannulation reaction of chromium carbenecomplexes

The palladium catalyzed homogeneous reduction of a variety of phenols with either sodium borohydride or triethylammonium formate are effected as their triflate esters. This transformation extends the usefulness of the benzannulation reaction of chromium carbene complexes with acetylenes and is exemplified for the synthetic targets angelicin, olivin, and chromomycinone.

O-allyl ether as a new protective group for oximes and its palladium-catalyzed deprotection

Oximes are protected by O-allyl ether formation, and their palladium-catalyzed deallylation using triethylammonium formate as a reductant proceeds smoothly in boiling ethanol under mild conditions offering a good protective method for oximes.

Catalytic Transfer Hydrogenation, A Chemo-Selective Reduction of Isoflavones to Isoflavanones

Abstract Isoflavones can be selectively reduced by catalytic transfer hydrogenation employing formic acid, ammonium formate or triethylammonium formate in the presence of 10% Pd/C. The reaction is simple, clean and gives fair yields of isoflavanones.

Palladium-catalyzed triethylammonium formate reduction of aryl triflates. A selective method for the deoxygenation of phenols

Phenols can be selectively deoxygenated by reduction of the corresponding aryl triflates with triethylammonium formate in the presence of a homogeneous palladium catalyst.