41908-11-6Relevant articles and documents
Rhodium-catalyzed reductive carbonylation of aryl iodides to arylaldehydes with syngas
Chen, Suqing,Liu, Zhenghui,Mu, Tiancheng,Wang, Peng,Yan, Zhenzhong,Yu, Dongkun,Zhao, Xinhui
, p. 645 - 656 (2020/05/14)
The reductive carbonylation of aryl iodides to aryl aldehydes possesses broad application prospects. We present an efficient and facile Rh-based catalytic system composed of the commercially available Rh salt RhCl3·3H2O, PPh3 as phosphine ligand, and Et3N as the base, for the synthesis of arylaldehydes via the reductive carbonylation of aryl iodides with CO and H2 under relatively mild conditions with a broad substrate range affording the products in good to excellent yields. Systematic investigations were carried out to study the experimental parameters. We explored the optimal ratio of Rh salt and PPh3 ligand, substrate scope, carbonyl source and hydrogen source, and the reaction mechanism. Particularly, a scaled-up experiment indicated that the catalytic method could find valuable applications in industrial productions. The low gas pressure, cheap ligand and low metal dosage could significantly improve the practicability in both chemical researches and industrial applications.
Acetamide/SO2Cl2 as an efficient reagent for Friedel-Craft's acylation of aromatic compounds under ultrasonic and microwave conditions
Satish Kumar, Mukka,Chinna Rajanna, Kamatala,Venkanna, Purugula,Venkateswarlu, Marri
, p. 1756 - 1759 (2014/03/21)
Acetamide/SO2Cl2 reagent has been developed for effective Friedel-Craft's acylation of aromatic compounds. Acylation of aromatic compounds with acetamide/SO2Cl2 was much more effective and faster than analogous (acetamide/SOCl2) and (acetamide/POCl 3) reagents even under conventional conditions. However, microwave and ultrasonic assisted reactions afforded high yields of products in very short reaction times (30-40 min under sonication and 3-4 min under microwave assisted conditions).
Competition between azido cleavage and triplet nitrene formation in azidomethylacetophenones
Ranaweera, Ranaweera A. A. Upul,Zhao, Yu,Muthukrishnan, Sivaramakrishnan,Keller, Christopher,Gudmundsdottir, Anna D.
, p. 1645 - 1655 (2011/09/14)
Photolysis of p- and m-azidomethylacetophenone (1a, 1b) in argon-saturated solutions yields predominantly imine 2a, 2b, whereas irradiation of 1a, 1b in oxygen-saturated solutions results in heterocycles 3a, 3b, aldehydes 4a, 4b and nitriles 5a, 5b. Density functional theory calculations place the energy of the first and second excited state of the triplet ketones (T1K and T 2K) in 1a, 1b in close proximity to each other. The triplet transition state for cleaving the CN bond in 1a, 1b to form azido and benzyl radicals 1aB, 1bB is located only 3 kcal mol-1 (1 kcal = 4.184 kJ) above T1K, indicating that azido cleavage is feasible. The calculations place the energy of the triplet azido group (TA) in 1a, 1b ～25 kcal mol-1 below T1K; thus, this process is also easily accessible via energy transfer. Further, the transition state barrier for TA to expel N2 and form triplet nitrenes is less than 1 kcal mol-1 above TA in 1a, 1b. Laser flash photolysis of 1a, 1b reveals the formation of the triplet excited ketones of 1a, 1b, which decay to form benzyl radicals 1aB, 1bB and triplet alkylnitrenes. The triplet ketones and the benzyl radicals are quenched with molecular oxygen at rates close to diffusion, whereas the triplet nitrenes react more slowly with oxygen (～5 × 105 M-1s-1). We conclude that the triplet alkylnitrenes intercept the benzyl radicals to form 2 in argon-saturated solution, whereas the benzyl radicals are trapped to form 4 in oxygen-saturated solution; thus, the triplet nitrenes react with oxygen to form 3. CSIRO 2010.
