50735-03-0Relevant articles and documents
Aldol-Tishchenko Reaction of α-Oxy Ketones: Diastereoselective Synthesis of 1,2,3-Triol Derivatives
Sedano, Carlos,Virumbrales, Cintia,Suárez-Pantiga, Samuel,Sanz, Roberto
supporting information, p. 3725 - 3734 (2021/07/02)
α-Oxy ketones, easily accessible by conventional routes, can be selectively deprotonated generating an enolate intermediate, which upon treatment with paraformaldehyde undergoes an aldol-Tishchenko reaction, leading to relevant 1,2,3-triol fragments in a totally diastereoselective manner. The excellent stereocontrol in the generation of a quaternary stereocenter is attributed to stereoelectronic effects in the Evans intermediate. This methodology allows overcoming some limitations of our previously reported strategy, based on the reaction of α-lithiobenzyl ethers with esters and paraformaldehyde, broadening the scope of the obtained polyols. Synthetic applications of this process include the preparation of a new dilignol model and some functionalized oxetanes.
Solvent free, light induced 1,2-bromine shift reaction of α-bromo ketones
An, Sejin,Moon, Da Yoon,Park, Bong Ser
, p. 6922 - 6928 (2018/10/24)
Photolysis of α-bromopropiophenones in acetonitrile results in formation of β-bromopropiophenones with good product selectivity, which can be coined as 1,2-Br shift reaction. The product selectivity increases when the reaction is done in neat or solid state, where only the 1,2-Br shift product is formed in some cases. The reaction is suggested to proceed by C–Br bond homolysis to give a radical pair, followed by disproportionation and conjugate addition of HBr to the α,β-unsaturated ketone intermediate. When the unsaturated intermediate is stabilized by an extra conjugation, the reaction stops at the stage, in which the unsaturated ketone becomes a major product. The synthetic method described in this research fits in a category of eco-friendly organic synthesis nicely since the reaction does not use volatile organic solvents and any other additives such as acid, base or metal catalysts, etc. Besides, the method fits into perfect atom economy, which does not give any side products. The synthetic method should find much advantage over other alternative methods to obtain β-bromo carbonyl compounds.
Unexpected Role of p-Toluenesulfonylmethyl Isocyanide as a Sulfonylating Agent in Reactions with α-Bromocarbonyl Compounds
Chen, Jiajia,Guo, Wei,Wang, Zhenrong,Hu, Lin,Chen, Fan,Xia, Yuanzhi
, p. 5504 - 5512 (2016/07/13)
The reactions of p-toluenesulfonylmethyl isocyanide (TosMIC) with α-bromocarbonyl compounds leading efficiently to α-sulfonated ketones, esters, and amides were reported, in which an explicit new role of TosMIC as the sulfonylating agent was uncovered for the first time. Mechanistic study by control experiments and DFT calculations suggested that the reaction is initiated by Cu(OTf)2-catalyzed hydration of TosMIC to form a formamide intermediate, which undergoes facile C-S bond cleavage under the mediation of a Cs2CO3 additive.