ABSTRACT
A catalyst-free multicomponent CDC reaction is rarely reported, especially for the intermolecular tandem CDC cyclization, which represents an important strategy for constructing cyclic compounds. Herein, a three-component tandem CDC cyclization by a Pummerer-type rearrangement to afford biologically relevant isoindolinones from aromatic acids, amides, and DMSO, is described. This intermolecular tandem reaction undergoes a C(sp(2) )-H/C(sp(3) )-H cross-dehydrogenative coupling, C-N bond formation, and intramolecular amidation. A notable feature of this novel protocol is avoiding a catalyst and additive (apart from oxidant).
ABSTRACT
The rhodium-catalyzed amidation of substituted benzoic acids with isocyanates by directed CH functionalization followed by decarboxylation to afford the corresponding N-aryl benzamides is demonstrated, in which the carboxylate serves as a unique, removable directing group. Notably, less common meta-substituted N-aryl benzamides are generated readily from more accessible para- or ortho-substituted groups by employing this strategy.
ABSTRACT
A facile and practical method that the copper powder-catalyzed Ullmann amination of aryl halides with aqueous methylamine under organic solvent- and ligand-free condition at 100 °C and in air gave N-arylamines as sole products in good to excellent yields. The presence of a small amount of air is essential. Other aliphatic primary amines show good to very high reactivity. Secondary amines and aniline are not reactive. Sensitive substituents (i.e., CHO, MeCO, CN and Cl) are tolerable in the reaction.
Subject(s)
Amines/chemistry , Copper/chemistry , Hydrocarbons, Halogenated/chemistry , Powders/chemistry , Solvents/chemistry , Amination , Catalysis , Molecular StructureABSTRACT
A very simple, efficient, and regiospecific protocol for aminobromination of a wide scope of beta-nitrostyrene derivatives with N-bromoacetamide (NBA) as nitrogen/bromine sources has been developed by using K(3)PO(4) as catalyst. The reaction proceeded smoothly and cleanly to give the bromoamines in good to excellent yields (78-99%) within 24 h in CH(2)Cl(2) at room temperature without protection of inert gases. A possible mechanism involving a nucleophilic conjugate addition was proposed.
Subject(s)
Acetamides/chemistry , Amines/chemistry , Bromine/chemistry , Phosphates/chemistry , Potassium Compounds/chemistry , Styrenes/chemistry , Catalysis , Crystallography, X-Ray , Methylene Chloride/chemistry , Molecular Structure , StereoisomerismABSTRACT
Silicon powder was found, for the first time, to be an efficient alternative to transition metal catalysts for aminobromination of alpha,beta-unsaturated carbonyl compounds and simple olefins with p-toluenesulfonamide (4-TsNH(2)) and NBS, affording the aminobrominated products in high yields and regio- and stereoselectivity. The high reactivity of electron-rich substrates reveals that the reaction has the electrophilic addition feature.
Subject(s)
Alkenes/chemistry , Bromine/chemistry , Silicon/chemistry , Sulfonamides/chemistry , Catalysis , Combinatorial Chemistry Techniques , Powders/chemistry , StereoisomerismABSTRACT
An efficient KI-catalyzed aminobromination of olefins has been developed with good to excellent yields and high regio- and stereoselectivities under transition metal-free conditions. A series of olefins, including alpha,beta-unsaturated carbonyl compounds and simple olefins, was studied. The reaction was performed in CH(2)Cl(2) using KI as the catalyst and TsNH(2) and NBS as the nitrogen and bromine sources.
Subject(s)
Alkenes/chemistry , Bromine/chemistry , Silicon/chemistry , Catalysis , Combinatorial Chemistry Techniques , HalogenationABSTRACT
The regio- and stereoselective aminobromination of alpha,beta-unsaturated ketones catalyzed by copper powder has been established with 4-TsNH(2) and NBS as the nitrogen/bromine sources, respectively. This method provides an easy access for preparation of vicinal aminohalo derivatives in the presence of 1 mol % catalyst. Electron-rich alpha,beta-unsaturated ketones afforded the corresponding aminobrominated products in excellent yields (up to 99.8%), revealing that the addition has an electrophilic feature.
Subject(s)
Copper/chemistry , Hydrocarbons, Brominated/chemical synthesis , Ketones/chemistry , Alkenes/chemistry , Benzenesulfonates/chemistry , Catalysis , Chalcone/chemistry , Crystallography, X-Ray , Ketones/chemical synthesis , Stereoisomerism , Sulfonamides/chemistry , Toluene/analogs & derivatives , Toluene/chemistryABSTRACT
An efficient and reusable catalyst with PdEDTA immobilized in an ionic liquid brush and a green procedure have been developed for coupling aryl iodides and bromides with phenylboronic acid. These reactions were conducted in water under aerobic conditions with water-insoluble or even solid aryl halides. The protocol has the advantages of excellent yields, environmental friendliness, and catalyst recyclability. There was no apparent loss of catalyst efficiency until the 10th cycle.
ABSTRACT
In the title compound, C(23)H(26)O(4), there is a dihedral angle of 83.7â (6)° between the two benzene rings. The five-membered rings have chair conformations.
