- Acid anhydrides and the unexpected N,N-diethylamides derived from the reaction of carboxylic acids with Ph3P/I2/Et3N
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The formation of acid anhydrides from the phosphorous-mediated activation of carboxylic acids was investigated. Under various systems, activation of benzoic acid in the presence of base led to the formation of benzoic anhydride at different rates depending on the reactivity of the reagents. Using the Ph3P-I2/Et3N combination, most aryl acids were converted into the corresponding anhydrides in high yields within 5-10 min. However, for nitro-substituted derivatives, unexpectedly, N,N-diethylamides were isolated without anhydride formation. These results indicated the pronounced effect of substituents in governing these potential side reactions which can significantly affect the yields of acylation reactions promoted by phosphonium species.
- Phakhodee, Wong,Duangkamol, Chuthamat,Wangngae, Sirilak,Pattarawarapan, Mookda
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supporting information
p. 325 - 328
(2016/01/12)
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- Simple synthesis of amides and weinreb amides Using PPh3 or PolymerSupported PPh3 and Iodine
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The combination of PPh3/I2 has been shown to be effective for the conversion of a range of carboxylic acids into secondary, tertiary, and Weinreb amides. Simplification of the procedure was possible with the use of polymer-supported PPh3/ I2. Weinreb amides produced with the use of polymer-supported PPh3 could be filtered through a short silica gel plug and used in further transformations. Thus, the use of polymer-supported PPh3 offers potential applicability to diversityoriented reactions. Formal total syntheses of apocynin and pratosine, as well as syntheses of anhydrolychorinone and hippadine, have been achieved through the use of this amide-forming method. An attempt has been made to gain insight into this reaction.
- Kumar, Amit,Akula, Hari Kiran,Lakshman, Mahesh K.
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experimental part
p. 2709 - 2715
(2010/08/05)
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- Transformation of thioamide compounds to corresponding amides using 12-Tungstosilicic acid
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12-Tungstosilicic acid (H4SiW12O40) is applied for the conversion of a series of thioamides to their corresponding oxo analogues in excellent yields in acetonitrile. In the case of thioketones, no reaction is observed under these conditions. The reusability of the catalyst also is investigated.
- Nasr-Esfahani, Masoud,Montazerozohori, Morteza,Moghadam, Majid,Mohammadpoor-Baltork, Iraj,Moradi, Sareh
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experimental part
p. 261 - 266
(2010/06/19)
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- A mild and convenient method for conversion of thioamides to their corresponding amides using acidified wet silica-supported permanganate under solvent-free conditions
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A mild and efficient method for conversion of thioamides to their corresponding amides is reported. A series of thioamides are transformed to their corresponding carbonyl compounds in good to excellent yields by acidified wet silica-supported permanganate under solid phase conditions.
- Nasr-Esfahani, Masoud,Moghadam, Majid,Mohammadpoor-Baltork, Iraj,Boostanifar, Mohammad Hasan
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experimental part
p. 141 - 146
(2009/04/10)
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- Acidified, wet, silica-supported tetrabutylammonium periodate: A convenient and mild reagent for conversion of thioamides to their corresponding amides under solvent-free conditions
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A series of thioamides are transformed to their corresponding oxo analogues in good to excellent yields with acidified, wet, silica-supported tetrabutylammonium periodate under solvent-free conditions.
- Nasr-Esfahani, Masoud,Moghadam, Majid,Mohammadpoor-Baltork, Iraj,Boostanifar, Mohammad Hasan
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experimental part
p. 2004 - 2009
(2010/01/17)
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- Efficient and convenient deprotection of thiocarbonyl to carbonyl compounds using 3-carboxypyridinium and 2,2′-bipyridinium chlorochromates in solution, dry media, and under microwave irradiation
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A synthetic utility of 3-carboxypyridinium (CPCC) and 2,2′- bipyridinium (BPCC) chlorochromates in deprotection reactions is reported. Different types of thioamides, thioureas, thiono esters, and thioketones are deprotected to their corresponding carbonyl compounds with these reagents in good to excellent yields. The reactions were carried out in solution, under solvent-free conditions, and under microwave irradiation. The results show that with both reagents the rates of the reactions and the yields are usually highest under microwave irradiation. Springer-Verlag 2003.
- Mohammadpoor-Baltork, Iraj,Memarian, Hamid Reza,Bahrami, Kiumars
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p. 411 - 418
(2007/10/03)
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- Bismuth(III) nitrate pentahydrate: A convenient and selective reagent for conversion of thiocarbonyls to their carbonyl compounds
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A variety of thioamides and thioureas are rapidly transformed to their oxo derivatives with Bi(NO3)3·5H2O in excellent yields. However, thiono esters and thioketones are converted to their corresponding carbonyl compounds in only poor yields. Bi(NO3)3·5H2O is relatively non-toxic, insensitive to air and inexpensive. These features coupled with the selective deprotection of thioamides and thioureas in the presence of thiono esters and thioketones make this method an attractive alternative to the existing routes for deprotection of thiocarbonyl compounds.
- Mohammadpoor-Baltork, Iraj,Khodaei, Mohammad Mehdi,Nikoofar, Kobra
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p. 591 - 594
(2007/10/03)
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- A convenient and inexpensive method for conversion of thiocarbonyl compounds to their oxo derivatives using oxone under solvent-free conditions
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A series of thioamides, thioureas and thioesters are transformed to their corresponding carbonyl compounds in good to excellent yields with oxone under solid phase conditions, while thioketones remained unchanged under these conditions.
- Mohammadpoor-Baltork, Iraj,Sadeghi, Majid M.,Esmayilpour, Karim
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p. 953 - 959
(2007/10/03)
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- Convenient transformation of thiocarbonyl to carbonyl group using benzyltriphenylphosphonium and n-butyltriphenylphosphonium peroxodisulfates
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Benzyltriphenylphosphonium and n-butyltriphenylphosphonium peroxodisulfates are stable and easily prepared oxidising agents. These reagents are able to convert different thioamides and thioureas to their oxygen analogues in good to excellent yields. Thiono esters are also transformed to esters in high yields. Thioketones such as thiobenzophenone and thiofluorenone are converted to their ketones in high yields while, 4-nitrothiobenzophenone, 2-aminothiobenzophenone and 4-chlorothiobenzophenone remained intact in the reaction mixture.
- Mohammadpoor-Baltork, Iraj,Sadeghi, Majid M. M.,Esmayilpour, Karim
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p. 348 - 350
(2007/10/03)
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- A facile and convenient method for deprotection of thiocarbonyls to their carbonyl compounds using oxone under aprotic and nonaqueous conditions
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The reaction of oxone as an inexpensive, stable, and commercially available reagent with thiocarbonyl compounds in refluxing acetonitrile has been studied. Primary, secondary, and tertiary thioamides and thioureas are converted to their oxo analogues efficiently. Thiono esters also are transformed to their corresponding esters, while thioketones remained intact under these conditions.
- Mohammadpoor-Baltork,Sadeghi,Esmayilpour
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