3651-81-8

Upstream product

• 1710-98-1 p-tert-butyl benzoyl chloride 
• 201230-82-2 carbon monoxide 
• 35779-04-5 1-tert-butyl-4-iodobenzene 
• 50-00-0 formaldehyd 
• 70356-09-1 1-(4-methoxyphenyl)-3-(4-tert-butylphenyl)propane-1,3-dione 
• 71228-00-7 1,3-bis(4-(tert-butyl)phenyl)propane-1,3-dione 

Downstream Products

• 138174-57-9 1,3,7,9-tetra-tert-butyl-2,2,8,8-tetramethyl-5,10-di(4-tert-butyl-benzoyl)-1,3,5,7,9,10-hexaaza-2,8-disila-4,6-distannadispiro{3.1.3.1}decane 
• 56108-12-4 4-tert-butylbenzamide 
• 138174-65-9 1,3,7,9-tetra-tert-butyl-2,2,8,8-tetramethyl-5,10-di(4-tert-butyl-benzoyl)1,3,5,7,9,10-hexaaza-2,8-disila-4,6-digermadispiro{3.1.3.1}decane 
• 78015-86-8 1,3-bis(4-(tert-butyl)phenyl)urea 

Relevant academic research and scientific papers

Deoxygenative Amination of Azine-N-oxides with Acyl Azides via [3 + 2] Cycloaddition

A transition-metal-free deoxygenative C-H amination reaction of azine-N-oxides with acyl azides is described. The initial formation of an isocyanate from the starting acyl azide via a Curtius rearrangement can trigger a [3 + 2] dipolar cycloaddition of polar N-oxide fragments to generate the aminated azine derivative. The applicability of this method is highlighted by the late-stage and sequential amination reactions of complex bioactive compounds, including quinidine and fasudil. Moreover, the direct transformation of aminated azines into various bioactive N-heterocycles illustrates the significance of this newly developed protocol.

Synthesis of Acyl Azides from 1,3-Diketones via Oxidative Cleavage of Two C-C Bonds

A metal-free PhI(OAc)2-mediated method for the synthesis of acyl azides through oxidative cleavage of 1,3-diketones is described. This method is shown to have a broad substrate scope, providing a useful tool for multiproduct synthesis in a single procedure. A possible reaction pathway is proposed based on mechanistic studies.

Synthesis of Amines, Carbamates and Amides by Multi-Step Continuous Flow Synthesis

We report the continuous flow synthesis of acyl azides in various continuous flow systems and demonstrate that liquid–liquid separation may be incorporated to prepare anhydrous solutions of the acyl azide, which may be subsequently reacted with appropriate nucleophiles to prepare amines, carbamates and amides within a fully integrated multi-step process in high yields (> 80 %). Interesting effects were also observed when preparing carbamates with long chain alcohols, whereby as the chain length of the alcohol increased the products could be made in high yield even without incorporation of the liquid–liquid separation module.

Visible light sensitization of benzoyl azides: Cascade cyclization toward oxindoles: Via a non-nitrene pathway

Visible light sensitization of benzoyl azides was examined in reaction with N-phenylmethacrylamides to afford biologically important oxindoles and spirooxindoles via a cascade cyclization under mild reaction conditions. Mechanistic studies suggested a non-nitrene pathway, where triplet benzoyl azides act as the reactive intermediate.

The challenge of palladium-catalyzed aromatic azidocarbonylation: From mechanistic and catalyst deactivation studies to a highly efficient process

Azidocarbonylation of iodoarenes with CO and NaN3, a novel Heck-type carbonylation reaction, readily occurs in an organic solvent-H 2O biphasic system to furnish aroyl azides at room temperature and 1 atm. The reaction is catalyzed by Xantphos-Pd and exhibits high functional group tolerance. The catalyst deactivation product, [(Xantphos)PdI2], can be reduced in situ with PMHS to Pd(0) to regain catalytic activity. In this way, the catalyst loading has been lowered to 0.2% without any losses in selectivity at nearly 100% conversion to synthesize a series of aroyl azides in 80-90% isolated yield on a gram scale. Alternatively, the ArCON3 product can be used without isolation for further transformations in situ, e.g., to isocyanates, ureas, benzamides, and iminophosphoranes. A detailed experimental and computational study has identified two main reaction pathways for the reaction. For both routes, Ar-I oxidative addition to Pd(0) is the rate-determining step. In the presence of CO in excess, the Ar-I bond is activated by the less electron-rich Pd center of a mixed carbonyl phosphine complex. Under CO-deficient conditions, a slightly lower energy barrier pathway is followed that involves Ar-I oxidative addition to a more reactive carbonyl-free (Xantphos)Pd0 species. Mass transfer in the triphasic liquid-liquid-gas system employed for the reaction plays an important role in the competition between these two reaction channels, uniformly leading to a common aroyl azido intermediate that undergoes exceedingly facile ArCO-N 3 reductive elimination. Safety aspects of the method have been investigated.

Palladium-catalyzed aromatic azidocarbonylation

Aryl iodides smoothly react with NaN3 and CO in the presence of a Pd/Xantphos catalyst to give aroyl azides (ArCON3) in 75-92 % yield. The reaction occurs under mild reaction conditions (1 atm, 20-50 °C) and exhibits high functional-group tolerance. (Xantphos=9,9-dimethyl-4,5- bis(diphenylphosphino)xanthene)