2902-69-4Relevant articles and documents
Synthesis of Trihalomethyl Ketones from Trihalomethyl Carbinols (Hal = Cl, Br) Using 2-Iodoxybenzoic Acid
Gulizhabaier,Rexit
, p. 809 - 815 (2021/06/12)
Abstract: An efficient method for the preparation of trihalomethyl (Cl, Br) ketones by the oxidation of trihalomethyl carbinols with 2-iodoxybenzoic acid in tert-butanol under heating has been developed. A series of trihalomethyl ketones have been synthesized through a simple, convenient, and environmentally friendly method with excellent yields.
London Dispersion Interactions Rather than Steric Hindrance Determine the Enantioselectivity of the Corey–Bakshi–Shibata Reduction
Eschmann, Christian,Song, Lijuan,Schreiner, Peter R.
supporting information, p. 4823 - 4832 (2021/02/01)
The well-known Corey–Bakshi–Shibata (CBS) reduction is a powerful method for the asymmetric synthesis of alcohols from prochiral ketones, often featuring high yields and excellent selectivities. While steric repulsion has been regarded as the key director of the observed high enantioselectivity for many years, we show that London dispersion (LD) interactions are at least as important for enantiodiscrimination. We exemplify this through a combination of detailed computational and experimental studies for a series of modified CBS catalysts equipped with dispersion energy donors (DEDs) in the catalysts and the substrates. Our results demonstrate that attractive LD interactions between the catalyst and the substrate, rather than steric repulsion, determine the selectivity. As a key outcome of our study, we were able to improve the catalyst design for some challenging CBS reductions.
Metal-Free Decarboxylative Trichlorination of Alkynyl Carboxylic Acids: Synthesis of Trichloromethyl Ketones
Jayaraman, Aravindan,Cho, Eunjeong,Irudayanathan, Francis Mariaraj,Kim, Jimin,Lee, Sunwoo
, p. 130 - 141 (2017/12/26)
2,2,2-Trichloroacetophenone derivatives were synthesized via decarboxylative trichlorination from arylpropiolic acids and trichloroisocyanuric acid (TCCA). The reaction was performed in the presence of water at room temperature, and the desired products were obtained in good yields. The reaction showed good functional group tolerance towards halide, cyano, nitro, ketone, ester and aldehyde groups. In addition, the 2,2,2-trichloroacetophenone derivatives were readily transformed into esters, amides, and hydrazides. Based on experiments with H218O (water-18O), we proposed a cationic reaction pathway as the mechanism and suggested two different pathways for producing aryl- and alkyl-substituted propiolic acids. (Figure presented.).
Continuous flow reaction system for the synthesis of 2,2,2-trichloroacetophenone derivatives and its application
Ko, Byeng Ha,Yu, Subeen,Song, Kwang Ho,Lee, Sunwoo
, p. 991 - 994 (2018/02/14)
A continuous flow reaction system was developed for the synthesis of 2,2,2-trichloroacetophenone derivatives. When aryl propiolic acids and water were mixed with trichloroisocyanuric acid in DMF at 5 °C, the 2,2,2-trichloroacetophenone derivatives were formed within 5 min with good yields. In addition, the resulting mixture was flowed to react with amines to give the corresponding benzamide. This flow reaction system provided higher yields within shorter times than the batch reaction system.
A study on reactions of an alkynylsilane with oxone-KX (X = Cl, Br, I) and its one-pot transformation into an amide/ester
Sriramoju, Vinodkumar,Jillella, Raveendra,Kurva, Srinivas,Madabhushi, Sridhar
supporting information, p. 560 - 562 (2017/03/30)
Oxyhalogenation reactions of a variety of alkynylsilanes were studied using oxone as mild oxidant and KCl, KBr, and KI as halogen sources. In this study, reaction of an alkynylsilane with oxone-KX (X = Cl or Br) produced trichloromethyl/tribromomethyl ketones inhigh yields. Under similar conditions, however, reactions of alkynylsilanes with oxone-KI were found to give exclusively 1,2,2-triiodovinyl derivatives in high yields. In this study, new methods were deveoped for effcient one-pot tranformation of alkynylsilanes into amides and esters by reaction with amines and alcohols respectively via trihalomethyl ketone.
A novel β-(oxy)alkyl radical during copper(I)-mediated stereoselective synthesis of (Z)-ene-1,4-diones in a reaction of 2,2,2-trichloro-1-phenylethanone
Ram, Ram N.,Tittal, Ram K.
supporting information, p. 2437 - 2440 (2016/05/19)
A novel β-(oxy)alkyl radical derived from trichloro methyl compound containing neither a suitably located C-C multiple bond nor a leaving group or a H-atom at the β-position of the radical in a reaction of 2,2,2-trichloro-1-phenyl-ethanone with 2 mol equiv each of CuCl and bpy in refluxing DCE under a N2 atm underwent intramolecular heterolysis (just like formation of intact radical cation-anion pair) during stereoselective radical dimerization to Z-ene-1,4-dione along with small amount of reductive dechlorination product. The stereochemistry was established by X-ray diffraction spectroscopy of various solid crystalline products.
Palladium catalyzed addition of arylboronic acid or indole to nitriles: Synthesis of aryl ketones
Das, Tuluma,Chakraborty, Amarnath,Sarkar, Amitabha
supporting information, p. 7198 - 7202 (2015/01/09)
Aryl ketones can be synthesized conveniently by a palladium catalyzed addition of arylboronic acid to nitriles in aqueous triflic acid. This catalytic system was extended to the addition of unprotected indoles to nitriles under a slightly modified condition to produce 3-acyl indoles in good yields.
Trichloromethyl ketones: Asymmetric transfer hydrogenation and subsequent Jocic-type reactions with amines
Perryman, Michael S.,Harris, Matthew E.,Foster, Jade L.,Joshi, Anushka,Clarkson, Guy J.,Fox, David J.
supporting information, p. 10022 - 10024 (2013/10/22)
Amino-amides are important pharmaceutical building-blocks. The enantioselective reduction of trichloromethyl ketones using ruthenium transfer hydrogenation catalysts is reported. The products react in a range of Jocic-type reactions to give enantiomerically enriched amino-amides.
Transition-metal-free transformation of aryl bromides into aromatic esters and amides via aryl trichloromethyl ketones
Dohi, Souya,Moriyama, Katsuhiko,Togo, Hideo
, p. 7815 - 7822 (2013/12/04)
A variety of aryl bromides have been treated with Mg and then chloral, followed by tBuOCl and subsequently alcohols or amines to produce the corresponding aromatic esters or amides in good yields via the formation of aryl trichloromethyl ketones as intermediates. These reactions are examples of a transition-metal-free one-pot preparation of aromatic esters and amides from aryl bromides. Aryl bromides have been treated with Mg and then chloral, followed by tBuOCl or tBuOCl with I2 as an additive, and subsequently alcohols or amines to form the corresponding aromatic esters and aromatic amides via aryl trichloromethyl ketones as intermediates. Copyright
