133446-39-6Relevant academic research and scientific papers
Metal-Free Synthesis of 4-Chloroisocoumarins by TMSCl-Catalyzed NCS-Induced Chlorinative Annulation of 2-Alkynylaryloate Esters
Norseeda, Krissada,Chaisan, Nattawadee,Thongsornkleeb, Charnsak,Tummatorn, Jumreang,Ruchirawat, Somsak
, p. 16222 - 16236 (2019/12/25)
4-Chloroisocoumarins can be conveniently prepared from 2-alkynylaryloate esters via the activation of alkynes by electrophilic chlorine, generated in situ from N-chlorosuccinimide (NCS) in the presence of 10 mol % trimethylsilyl chloride (TMSCl), which leads to 6-endo-dig-selective chlorinative annulation to give the desired products in moderate to quantitative yields. The procedure employs readily available reagents and can be conveniently carried out on a wide scope of substrates under mild conditions (0 °C to rt). Furthermore, the reaction is scalable for gram-scale preparation of 4-chloroisocoumarins. Additionally, 4-bromo- and 4-iodoisocoumarins can be prepared in moderate to good yields by replacing NCS with N-bromosuccinimide (NBS) and N-iodosuccinimide (NIS), respectively.
Rhodium(II)-Catalyzed Cyclization Reactions of Alkynyl-Substituted α-Diazo Ketones
Padwa, Albert,Krumpe, Keith E.,Gareau, Yves,Chiacchio, Ugo
, p. 2523 - 2530 (2007/10/02)
Treatment of several o-alkynyl-substituted α-diazoacetophenone derivatives with rhodium(II) carboxylates results in the formation of substituted indenones.The simplest mechanism accounting for the results involves addition of a rhodium-stabilized carbenoi
