- β-oxopropyl formate as a formylating agent of sterols
-
Propargylic alcohol reacts with formic acid in the presence of mononuclear catalysts of ruthenium to selectively afford β-oxopropyl formate which has been shown as an excellent mild formylating agent of sterols when the reaction is catalyzed by 1,5-diazabicyclo[4.3.0]non-5-ene (DBN).
- Kabouche, Ahmed,Kabouche, Zahia
-
-
Read Online
- Reaction of C2-symmetrical dialkoxysilanes R1O-Si(R2)2-OR1 with the two Vilsmeier-Haack complexes POCl3·DMF and (CF3SO2)2O·DMF: An efficient one-step conversion to the
-
The two electrophilic Vilsmeier-Haack complexes POCl3·DMF 1 and (CF3SO2)2O·DMF 2 react with C2-symmetrical dialkoxysilanes R1O-Si(R2)2-OR1 (R1=(-)-menthyl o
- Cohen,Kotlyar,Koeller,Lellouche
-
-
Read Online
- DMF·HCl as a versatile and straightforward N- and O-formylating agent
-
Inspired by the serendipitous isolation of N-formylpiperazines when we attempted the synthesis of a series of piperazines, we have developed a straightforward methodology for the N- and O- formylation of secondary cyclic amines, anilines and steroids, respectively. Such approach is based on the hitherto non-reported use of DMF·HCl complex, as a versatile and easily-available formylating system that can be stored without apparent loss of activity.
- Ramírez-Vázquez, Dulce G.,Vi?as-Bravo, Omar,Martínez-Pascual, Roxana,Pérez-Picaso, Lemuel,Castro-Cerritos, Karla Viridiana
-
supporting information
p. 585 - 592
(2020/11/19)
-
- Polyvinylpolypyrrolidoniume tribromide as new and metal-free catalyst for the formylation and trimethylsilylation of hydroxyl group
-
Trimethylsilylation of alcohols was achieved using 1,1,1,3,3,3- hexamethyldisilazane (HMDS) as silylating agent, in the presence of polyvinylpolypyrrolidoniume tribromide in acetonitrile at room temperature. Also a variety of alcohols were converted into alkyl formates by ethyl formate and a catalytic amount of polyvinylpolypyrrolidoniume tribromide under solvent free conditions at room temperature.
- Ghorbani-Choghamarani, Arash,Goudarziafshar, Hamid,Zamani, Parisa
-
scheme or table
p. 1207 - 1210
(2012/01/05)
-
- Highly efficient formylation of alcohols, thiols and aniline derivatives by a heterogeneous (HCOOH/SiO2) system under microwave irradiation and solvent-free conditions
-
A simple, rapid and efficient microwave-assisted procedure for the formylation of aniline derivatives and alcohols, using a heterogeneous (HCOOH/SiO2) system under solvent-free conditions is reported. The method is applied to a set of amines, alcohols and thiols and short reaction times (10 min) with high yields are reported. This protocol introduces a practical and viable green technology of solvent-free and catalyst-free reactions.
- Ghorbani-Vaghei, Ramin,Veisi, Hojat,Amiri, Mostafa,Chegini, Mohammad,Karimi, Mehdi,Dadamahaleh, Somayeh Akbari,Sedrpoushan, Alireza
-
experimental part
p. 39 - 43
(2010/09/03)
-
- Silica sulfuric acid and AI(HSO4)3: As efficient catalysts for the formylation of alcohols by using ethyl formate under heterogeneous conditions
-
A mixture of ethyl formate and a catalytic amount of silica sulfuric acid or Al(HSO4)3 as suitable formylating systems can formylate various alcohols to their corresponding formate ester derivatives under mild, nearly neutral and heterogeneous conditions at room temperature with good to excellent yields.
- Zolfigol, Mohammad Ali,Chehardoli, Gholamabbas,Dehghanian, Mina,Niknam, Khodabakhsh,Shirini, Farhad,Khoramabadi-Zad, Ahmad
-
experimental part
p. 885 - 889
(2009/12/04)
-
- A simple, convenient and chemoselective formylation of sterols by Vilsmeier reagent
-
Vilsmeier reagent (DMF-POCl3) was used as an efficient formylating agent. Several sterols having sec-hydroxyl group at 3/17-position have been modified into respective formate esters. The method is simple, mild, chemoselective and provides sec-alcoholic protection in good yields.
- Srivastava, Vandana,Negi, Arvind Singh,Kumar,Gupta
-
p. 632 - 638
(2007/10/03)
-
- Conversion of alkyl halides into alcohols via formyloxylation reaction with DMF catalyzed by silver salts
-
The transformation of alkyl halides into alcohols via a two-step process based on the reaction with DMF catalyzed by Ag(I) salts followed by acid or basic hydrolysis of the intermediate formate ester has been evaluated. The results show that a large variety of primary and some secondary alkyl halides can be transformed efficiently into the corresponding alcohols, making this alkyl halide to alcohol interconversion a valuable alternative to the existing procedures, particularly in molecules with labile functional groups that are generally involved in multistep synthesis. Georg Thieme Verlag Stuttgart.
- Abad, Antonio,Agullo, Consuelo,Cunat, Ana C.,Navarro, Ismael
-
p. 3355 - 3361
(2007/10/03)
-
- Silphos [PCl3-n(SiO2)n]: A heterogeneous phosphine reagent for formylation and acetylation of alcohols and amines with ethyl formate and acetate
-
Alcohols and amines are formylated and acetylated in the presence of Silphos [PCl3-n(SiO2)n] in ethyl formate and ethyl acetate in high to excellent yields. This procedure provides a method to separate the product by a simple filtration.
- Iranpoor, Nasser,Firouzabadi, Habib,Jamalian, Arezu
-
p. 7963 - 7966
(2007/10/03)
-
- Vilsmeier-Haack Reagents. Novel Electrophiles for the One-Step Formylation of O-Silylated Ethers to O-Formates
-
Various O-silylated substrates were effectively converted in one-step to their corresponding O-formates using electrophilic racemic and homochiral Vilsmeier-Haack reagents. Reactivity trends of these transformations were examined that, specifically, empha
- Lellouche, Jean-Paul,Kotlyar, Vadim
-
p. 564 - 571
(2007/10/03)
-
- Reptilian chemistry: volatile compounds from paracloacal glands of the American crocodile (Crocodylus acutus).
-
The secretion of the paracloacal glands of the American crocodile (Crocodylus acutus) contains over 80 lipophilic compounds, including saturated and unsaturated long-chain alcohols along with their formic, acetic, and butyric acid esters, and several isoprenoids. Most of these compounds were identified on the basis of mass spectra, obtained by GC-MS. In addition, identification of the major components was supported by infrared spectra obtained by GC-FTIR. Major differences are indicated in the composition of the paracloacal gland secretion of C. acutus and that of another crocodylid, the African dwarf crocodile (Osteolaemus tetraspis).
- Garcia-Rubio, Silvina,Attygalle, Athula B,Weldon, Paul J,Meinwald, Jerrold
-
p. 769 - 781
(2007/10/03)
-
- Selective formylation of alcohols in the presence of phenols with chloral
-
Primary and secondary alcohols were formylated selectively in the presence of phenols by stirring with chloral in acetone over anhydrous K2CO3 at ambient temperatures in high yields.
- Ram, Ram N,Meher, Nabin Kumar
-
p. 2997 - 3001
(2007/10/03)
-
- Solvolysis of sterol tosylates in aqueous dimethylformamide
-
It has been established that the heating of the sterol tosylates (1a - c) in aqueous dimethylformamide in the presence of sodium acetate leads to the formation of the 3α,5-cyclo-6β-alcohols (2), the sterols (3), the 3,5-dienes (4), and the sterol formates (5).
- Kovganko,Survilo
-
p. 324 - 327
(2007/10/03)
-
- Preparation of formate esters from O-TBDMS/O-TES protected alcohols. A one-step conversion using the Vilsmeier-Haack complex POCl3/DMF
-
O-tert-Butyldimethylsilylated (O-TBDMS) or O-triethylsilylated (O-TES) alcohols were converted in one step to their corresponding formates under Vilsmeier-Haack conditions (POCl3/DMF). The scope and limitations of this novel reaction for interconverting alcohol protecting groups are described.
- Koeller, Sylvain,Lellouche, Jean-Paul
-
p. 7043 - 7046
(2007/10/03)
-
- Cs2CO3 promoted O-alkylation of alcohols for the preparation of mixed alkyl carbonates
-
The presence of cesium carbonate and tetrabutylammonium iodide (TBAI) facilitated efficient O-alkylation of alcohols with alkyl halides, giving rise to the exclusive formation of mixed alkyl carbonates. The cesium effect was also examined comparatively with other alkali carbonates.
- Chu,Dueno,Kyung Woon Jung
-
p. 1847 - 1850
(2007/10/03)
-
- Tf2O/Amide adducts: Versatile reagents for the synthesis of imidates and amidines
-
The Vilsmeier reagents generated from tertiary and secondary aliphatic and aromatic amides and trifluoromethanesulfonic anhydride (Tf2O) reacted with different nucleophiles (ROH, RSH, RNH2) affording the relative iminium and amidinium salts. The former, stable at room temperature, were easily transformed into the corresponding esters or O-alkyl thioesters by treatment with OH- or SH-.
- Sforza, Stefano,Dossena, Arnaldo,Corradini, Roberto,Virgili, Eliana,Marchelli, Rosangela
-
p. 711 - 714
(2007/10/03)
-
- Selective acetylation of primary alcohols: Acetyl and formyl transfer reactions with copper(II) salts
-
The efficient esterification of primary and secondary alcohols in acetic acid was achieved in the presence of Cu(NO3)2. 3H20 in high yields. Selective acetylation of primary in the presence of secondary hydroxyl groups in excellent yields were performed in EtOAc. Formylation of primary and secondary alcohols was also achieved easily in ethyl formate. High retention of configuration was observed in the acetylafion and formylation of (-) menthol in the presence of Cu(NO3)2. 3H20 and Cu(OAC)2. H2O.
- Iranpoor,Firouzabadi,Zolfigol
-
p. 1923 - 1934
(2007/10/03)
-
- Acetylation and formylation of alcohols with triphenylphosphine and carbon tetrabromide in ethyl acetate or ethyl formate
-
Alcohols were acetylated or formylated with triphenylphosphine and carbon tetrabromide in ethyl acetate or ethyl (or methyl) formate at room temperature. THP or TBDMS ether of primary alcohol got converted into formate or acetate under the experimental conditions employed in one pot operation.
- Hagiwara, Hisahiro,Morohashi, Kimie,Sakai, Hitoshi,Suzuki, Toshio,Ando, Masayoshi
-
p. 5845 - 5852
(2007/10/03)
-
- FORMYLATION REACTION USING THE OZONOLYSATE OF OXAZOLE
-
The ozonolysis of oxazole (1) did not give formic anhydride (3), but gave N-formylformamide (5), which reacted with various nucleophiles to afford the corresponding formylated products in high yield.This formylating reaction should be useful in the organic syntheses.
- Kashima, Choji,Arao, Hideki,Hibi, Shigeki,Omote, Yoshimori
-
p. 1561 - 1562
(2007/10/02)
-
- POLYMER-SUPPORTED PHOSPHINE-HALOGEN COMPLEXES - 4. IMPROVED FORMYLATION OF ALCOHOLS WITH DIMETHYLFORMAMIDE
-
A new, very convenient procedure for smooth conversion of primary and secondary alcohols to their corresponding formic acid esters is described.This is based on the use of modified Vilsmeier-Haak adducts, obtained from N,N-dimethylformamide and polymer-supported triarylphosphine-halogen complexes.
- Caputo, Romualdo,Ferreri, Carla,Palumbo, Giovanni
-
p. 1629 - 1636
(2007/10/02)
-
- The Invention of New Radical Chain Reactions. Part 11. A New Method for the Generation of Tertiary Radicals from Tertiary Alcohols
-
A convenient procedure for the radical deoxygenation of tertiary alcohols has been invented using the double half esters of oxalic acid with the t-alcohol and N-hydroxypyridine-2-thione.Decomposition of this type of ester in the presence of 1,1-dimethylethane- or (better) 1,1-diethylpropane-thiol gave the corresponding hydrocarbons in good yield.It has been shown that the oxalate fragmentation is not concerted, but involves a stepwise loss of carbon dioxide.Tertiary alcohols are also a convenient source of radicals for addition to siutable alkenes with formation of quaternary centres.
- Barton, Derek H. R.,Crich, David
-
p. 1603 - 1612
(2007/10/02)
-
- A New Method for the Radical Deoxygenation of Tertiary Alcohols
-
Tertiary alcohols can be deoxygenated in a radical chain reaction based on their mixed oxalate esters with N-hydroxy-2-thiopyridone, these esters being obtained directly from the alcohols and oxalyl chloride etc. or via their trimethylsilyl derivatives.
- Barton, Derek H. R.,Crich, David
-
p. 774 - 775
(2007/10/02)
-
- Conversion of Thiocarbonyl Compounds into their Corresponding Oxo-derivatives using Benzeneseleninic Anhydride
-
A series of thiocarbonyl compounds including xanthates, thioesters, thioureas, thiocarbonates, and thiones have been converted into their oxo-analogues by treatment with benzeneseleninic anhydride in tetrahydrofuran at room temperature.Except for readily enolised thiones where further oxidation can take place, the method works well and compares favourably with other literature procedures.One example of a selenocarbonyl ester was likewise converted efficiently into the corresponding ester.
- Cussans, Nigel J.,Ley, Steven V.,Barton, Derek H. R.
-
p. 1650 - 1653
(2007/10/02)
-
- Preparation of N-Formylpyridones - Selective Esterification of Primary, Secondary and Tertiary Alcohols with N-Acylpyridones
-
Formylation of monohydroxypyridines 1-3 with formic acid in the presence of dicyclohexylcarbodiimide in dichloromethylene yields N-formyl-4- (4), N-formyl-2-pyridone (5), and 3-(formyloxy)pyridine (6), resp.These acylpyridones react with prim., sec., and tert. alcohols with selectivity decreasing reactivity to give the formyl esters 7.
- Effenberger, Franz,Keil, Michael,Bessey, Eberhard
-
p. 2110 - 2119
(2007/10/02)
-