Enantioselective Synthesis of 3,4-Dihydroisoquinolin-1(2<i>H</i>)-ones by Nickel-Catalyzed Denitrogenative Annulation of 1,2,3-Benzotriazin-4(3<i>H</i>)-ones with Allenes
A denitrogenative annulationreaction of 1,2,3-benzotriazin-4(3H)-ones with allenes catalyzed by a nickel-phosphine complex to produce a variety of substituted 3,4-dihydroisoquinolin-1(2H)-ones in a regioselective manner is described. A highly enantioselective version, as well as structural evidence for the mechanistic course of this reaction, is also presented.
Visible-light-induced denitrogenative phosphorylation of benzotriazinones: a metal- and additive-free method for accessing <i>ortho</i>-phosphorylated benzamide derivatives
3-benzotriazinones was achieved. With the use of eosin Y as a photoredox catalyst, N,N-diisopropylethylamine as a base, CH3CN–H2O as a solvent and sunlight or a blue LED as a light source, a variety of aryl-phosphonates, aryl-phosphinates, and aryl-phosphine oxides were efficiently prepared. In addition, B2pin2 instead of P-nucleophiles as a radical acceptor was also demonstrated. The key advantages of this
NaNO2/I2 as an alternative reagent for the synthesis of 1,2,3-benzotriazin-4(3H)-ones from 2-aminobenzamides
作者:Dinesh S. Barak、Sushobhan Mukhopadhyay、Dipak J. Dahatonde、Sanjay Batra
DOI:10.1016/j.tetlet.2018.12.025
日期:2019.1
An efficient transformation of 2-aminobenzamides to 1,2,3-benzotriazin-4(3H)-ones in the presence of sodium nitrite (NaNO2) and Iodine (I2) is described. The reaction is proposed to proceed via formation of nitrosyl halide that induces nitrosylation of the amino group of 2-aminobenzamide leading to diazotization followed by intramolecular cyclization.
1,2,3-Benzotriazin-4(3H)-ones and 1,2,3,4-benzothiatriazine 1,1(2H)-dioxide reacted with isocyanides in the presence of a palladium catalyst to give 3-(imino)isoindolin-1-ones and 3-(imino)thiaisoindoline 1,1-dioxides, respectively, in high yield. An intermediate azapalladacycle was generated through denitrogenation of the triazine moiety, and an isocyanide was incorporated therein.