Electrochemical oxidative cyclization of: N -allylcarboxamides: Efficient synthesis of halogenated oxazolines
Herein, we reported an efficient and sustainable intramolecular electrochemical cyclization of N-allylcarboxamides for the synthesis of various halogenated oxazolines. This method was conducted in a simple undivided cell by employing lithium halogen salts
Electrochemical Chalcogenation of β,γ-Unsaturated Amides and Oximes to Corresponding Oxazolines and Isoxazolines
The current report represents a transition-metal-free synthesis of oxazoline and isoxazoline derivatives by a tandem electro-oxidative chalcogenation-cyclization process. Both C?Se and C?S bond-forming protocols were developed without using any external oxidant and the reaction was performed at room temperature, open to the air. Using this methodology, 29 substituted oxazoline and 16 substituted isoxazoline derivatives were synthesized with up to 91% isolated yield. (Figure presented.).
Nickel(0)-Catalyzed N-Allylation of Amides and p-Toluenesulfonamide with Allylic Alcohols under Neat and Neutral Conditions
Nickel(0)-catalyzed direct N-allylation of amides and p-toluenesulfonamide with allylic alcohols took place in the presence of Ni0–diphosphine complexes. The corresponding N-allylated (and/or N,N-diallylated) products were obtained in moderate to high yields under neutral conditions.
Efficient conversion of acids and esters to amides and transamidation of primary amides using OSU-6
OSU-6, an MCM-41 type hexagonal mesoporous silica with strong Bronsted acid properties, has been used to promote the high-yield conversion of carboxylic acids and esters to carboxamides as well as transamidations of primary amides in a one-pot solventless approach. A metal-free heterogeneous catalyst that promotes all of these processes has not been previously reported. OSU-6 enables these transformations to proceed in shorter times and at lower temperatures for a broad range of substrates. An added benefit is that the catalyst can be recycled and reused multiple times without significant loss of activity.
Nammalwar, Baskar,Muddala, Nagendra Prasad,Watts, Field M.,Bunce, Richard A.
p. 9101 - 9111
(2015/11/09)
An iron-catalysed synthesis of amides from nitriles and amines
The cheap, commercially available iron complex, Fe(NO3)3·9H2O, has been used to catalyse the formation of amides by the addition of amines to nitriles.
Allen, C. Liana,Lapkin, Alexei A.,Williams, Jonathan M.J.
experimental part
p. 4262 - 4264
(2009/10/26)
Hydrotropic solubilization of paclitaxel: Analysis of chemical structures for hydrotropic property
Purpose. To identify hydrotropic agents that can increase aqueous paclitaxel (PTX) solubility and to study the chemical structures necessary for hydrotropic properties so that polymeric hydrotropic agents can be synthesized. Methods. More than 60 candidate hydrotropic agents (or hydrotropes) were tested for their ability to increase the aqueous PTX solubility. A number of nicotinamide analogues were synthesized based on the observation that nicotinamide showed a favorable hydrotropic property. The identified hydrotropes for PTX were used to examine the structure-activity relationship. Results. N,N-Diethylnicotinamide (NNDENA) was found to be the most effective hydrotropic agent for PTX. The aqueous PTX solubility was 39 mg/ml and 512 mg/ml at NNDENA concentrations of 3.5 M and 5.95 M, respectively. These values are 5-6 orders of magnitude greater than the intrinsic solubility of 0.30 ± 0.02 μg/ml. N-Picolylnicotinamide, N-allylnicotinamide, and sodium salicylate were also excellent hydrotropes for PTX. Solubility data showed that an effective hydrotropic agent should be highly water soluble while maintaining a hydrophobic segment. Conclusions. The present study identified several hydrotropic agents effective for increasing aqueous solubility of PTX and analyzed the structural requirements for this hydrotropic property. This information can be used to find other hydrotropic compounds and to synthesize polymeric hydrotropes that are effective for PTX and other poorly water-soluble drugs.
Lee, Jaehwi,Lee, Sang Cheon,Acharya, Ghanashyam,Chang, Ching-Jer,Park, Kinam
p. 1022 - 1030
(2007/10/03)
Structure and antiinflammatory activity of isonicotinic and nicotinic amides