96908-21-3

Upstream product

• 2403-27-2 1-(4-bromophenyl)-3-phenyl-2-propen-1-one 
• 766-96-1 4-bromo-1-ethynylbenzene 
• 61650-22-4 N-(pivaloyloxy)benzamide 
• 3185-50-0 N-(4-bromophenethyl)benzamide 
• 582-61-6 benzoyl azide 
• 126443-12-7 4'-bromo-4-methoxy-trans-chalcone 
• 100-46-9 benzylamine 
• 99-73-0 para-bromophenacyl bromide 
• 72997-91-2 4-(4-bromo-phenyl)-(trans-3-phenyl-aziridin-2-yl)-ketone 
• 2039-82-9 1-bromo-4-ethenyl-benzene 
• 14367-97-6 1-(4-bromophenyl)-2-nitro-1-ethanone 
• 707-07-3 orthobenzoic acid trimethyl ester 
• 72571-06-3 5-(4-bromophenyl)oxazole 
• 591-50-4 iodobenzene 

Downstream Products

• 370598-02-0 4-(2-phenyl-oxazol-5-yl)-benzenesulfonyl chloride 

Relevant academic research and scientific papers

Metal-free iodine(iii)-promoted synthesis of 2,5-diaryloxazoles

A nonmetal-catalyzed oxidative cyclization to achieve 2,5-disubstituted oxazoles from inexpensive and readily available substituted chalcone, (diacetoxyiodo)benzene (PIDA) and ammonium acetate (NH4OAc) at room temperature is described. The reaction forms a variety of 2,5-diaryloxazoles in good to excellent yields with broad substrate scope under mild conditions without the requirement of ligands and additional bases.

Synthesis of 2,5-disubstituted oxazoles: Via cobalt(III)-catalyzed cross-coupling of N -pivaloyloxyamides and alkynes

An efficient synthesis of 2,5-disubstituted oxazoles via Co(iii) catalysis is described herein. The synthesis is achieved under mild conditions through [3+2] cycloaddition of N-pivaloyloxyamides and alkynes. The reaction operates through an internal oxidation pathway and features a very broad substrate scope. The one-step synthesis of natural products such as texamine and balsoxin has been demonstrated via this protocol.

N -Bromosuccinimide as a Brominating Agent for the Transformation of N -H (or N -Benzyl) Ketoaziridines into Oxazoles

A novel procedure for the direct synthesis of 2,5-diaryloxazoles starting from N-H ketoaziridines is described. The method proceeds via the in situ formation of N-bromoketoaziridines in the presence of N-bromosuccinimide followed by the generation of intermediate azomethine ylides. A plausible mechanism for this transformation is proposed.

Iodine catalysed intramolecular C(sp3)-H functionalization: synthesis of 2,5-disubstituted oxazoles from N-arylethylamides

Iodine catalyzed synthesis of 2,5-disubstituted oxazoles from N-arylethylamides through intramolecular C(sp3)-H functionalization under metal-free conditions is described. The method is tolerable to a wide range of substrates having a variety of functional groups with moderate to good yields of the products.

Copper-catalyzed oxidative cyclization of chalcone and benzylic amine leading to 2,5-diaryl oxazoles via carbon-carbon double bond cleavage

A copper-catalyzed oxidative cyclization of chalcone with benzylic amine is achieved, providing 2,5-diaryl oxazoles in moderate to good yields. The procedure employs O2 as a clean oxidant and involves an oxidative cleavage of the CC bond as the key step.

Reaction of alkynes and azides: Not triazoles through copper-acetylides but oxazoles through copper-nitrene intermediates

Well-defined copper(I) complexes of composition [Tpm* ,BrCu(NCMe)]BF4 (Tpm*,Br=tris(3,5- dimethyl-4-bromo-pyrazolyl)methane) or [Tpa* Cu]PF6 (Tpa=tris(3,5-dimethyl-pyrazolylmethyl)amine) catalyze the formation of 2,5-disubstituted oxazoles from carbonyl azides and terminal alkynes in a direct manner. This process represents a novel procedure for the synthesis of this valuable heterocycle from readily available starting materials, leading exclusively to the 2,5-isomer, attesting to a completely regioselective transformation. Experimental evidence and computational studies have allowed the proposal of a reaction mechanism based on the initial formation of a copper-acyl nitrene species, in contrast to the well-known mechanism for the copper-catalyzed alkyne and azide cycloaddition reactions (CuAAC) that is triggered by the formation of a copper-acetylide complex.

Practical oxazole synthesis mediated by iodine from α-bromoketones and benzylamine derivatives

The reagent system of I2/K2CO3 could efficiently promote the oxazole synthesis from α-bromoketones and benzylamine derivatives in DMF. This method was not only suitable for 2,5-diaryl oxazole synthesis but also for 2,4,5-trisubstituted oxazole and 5-alkyl/alkenyl oxazole synthesis. Furthermore, this method was successfully applied to a one-step synthesis of a natural product halfordinol in 62% yield.

I2/TBHP-mediated domino process: A convenient route to 1,3-oxazole derivatives

A practical and simple synthesis of 2,5-disubstituted oxazoles was developed via a TBHP (tert-butyl hydroperoxide)/I2-mediated domino strategy. The reaction proceeds in series, giving rise to the formation of an intermolecular C-N bond and an intramolecular C-O bond, which yield oxazole derivatives simultaneously. The reaction gave the desired products from readily available substrates under mild conditions.

A new approach to ring expansion of keto aziridines to 2,5-diaryloxazoles

Ring expansion of keto aziridines to the corresponding 2,5-diaryl oxazoles in the presence of dicyclohexyl carbodiimide and iodine under refluxing acetonitrile conditions is described. A plausible mechanism is proposed. Georg Thieme Verlag Stuttgart New York.

C-C bond cleavage of keto-aziridines; synthesis of oxazoles via regio-controlled ring expansion

The ring expansion of keto-aziridines to the corresponding 2,5-diaryloxazoles in the presence of iodine in refluxing dimethyl sulfoxide, is described. A plausible mechanism for the synthesis of 2,5-diaryloxazoles is proposed.