نتایج جستجو برای: hydrazides
تعداد نتایج: 849 فیلتر نتایج به سال:
A novel method to synthesise 2-arylindoles is demonstrated via direct arylation of indoles with arylsulfonyl hydrazides. Under the optimized reaction conditions, the reaction well tolerates a wide variety of functional groups to afford structurally diverse 2-arylindoles in good to excellent yields at 70 °C.
The cleavage of gelatin to smaller molecular units by aqueous hydroxylamine or hydrazine under relatively mild conditions of temperature and pH has suggested the existence of “ester-like” or imide linkages in this protein (1). The amide bonds of gelatin were cleaved only to a minor extent and could not account for the large change in molecular weight. It is known, however, that prolonged treatm...
Rapid and highly efficient synthesis of 2- or 2,5-substituted 1,3,4-oxadiazoles by the condensation of aryl carboxylic acid hydrazides and orthoesters can be achieved under microwave irradiation using an unmodified commercial over in unsealed vessels.
rapid and highly efficient synthesis of 2- or 2,5-substituted 1,3,4-oxadiazoles by the condensation of aryl carboxylic acid hydrazides and orthoesters can be achieved under microwave irradiation using an unmodified commercial over in unsealed vessels.
A range of highly enantioenriched primary allylic amines underwent palladium-catalyzed oxidative coupling with sulfonyl hydrazides open to air at room temperature to give structurally diverse allylic sulfones in moderate to excellent yields with excellent retention of ee.
The 1,3,4-oxadiazole is an aromatic heterocycle valued for its low-lipophilicity in drug development. Substituents at the 2and/or 5-positions can modulate the heterocycle's electronic and hydrogen bondaccepting capability, while exploiting its use as a carbonyl bioisostere. A new approach to 1,3,4oxadiazoles is described wherein a-bromo nitroalkanes are coupled to acyl hydrazides to deliver the...
The coupling reaction of benzoic acid and nicotinic acid hydrazides with N- protected L-amino acids including valine, leucine, phenylalanine, glutamic acid and tyrosine is reported. The target compounds, N-Boc-amino acid-(N;-benzoyl)- and N- Boc-amino acid-(N;-nicotinoyl) hydrazides 5a-5e and 6a-6e were prepared in very high yields and purity using N-[(dimethylamino)-1H-1,2,3-triazolo[4,5-b]pyr...
In the title compound, C(2)H(5)N(3)O(3), the hydroxamic group adopts an anti orientation with respect to the hydrazide group. In the crystal, mol-ecules are connected by N-H⋯O and O-H⋯N hydrogen bonds into zigzag chains along the c axis.
The first structurally authenticated [2+2] cycloaddition products of any transition metal hydrazide complexes are reported; cycloaddition products of transition metal hydrazides with alkynes and heteroalkynes have been obtained for the first time; these are the first structurally authenticated cycloaddition products for any transition metal M=NNR(2) functional group.
An efficient one-pot tandem cyclization/[3 + 2] cycloaddition reaction of N'-(2-alkynylbenzylidene)hydrazides with ethyl 4,4,4-trifluorobut-2-ynoate under silver triflate-catalyzed or electrophile-mediated conditions is described. Various trifluoromethylated pyrazolo[5,1-a]isoquinolines were afforded in moderate to excellent yield by this developed method.
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