A facile method for the synthesis of 3-substituted 3H-indol-3-ols has been developed. Thus, 2-isocyanophenyl ketones are allowed to react with various Grignardreagents to give the corresponding desired indolol derivatives in generally fair to good yields. The formation of 3-aryl-2,3-dimethylindolin-3-ols by the reaction of 2-isocyanobenzophenones with 2 M amounts of methylmagnesium bromide is also
Two-pot synthesis of N,N-disubstituted 4H-3,1-benzothiazin-2-amines from aryl(2-isothiocyanatophenyl)methanones and secondary amines
作者:Kazuhiro Kobayashi、Yuuki Kanbe
DOI:10.1016/j.tet.2011.10.045
日期:2011.12
A convenient synthesis of N,N-disubstituted 4H-3,1-benzothiazin-2-amines from aryl(2-isothiocyanatophenyl)methanones using a two-pot procedure has been developed. Thus, treatment of these isothiocyanato ketones with secondary amines gave the corresponding keto thioureas, which were allowed to react with sodium borohydride or methylmagnesium bromide to afford 1,1-dialkyl-3-2-[aryl(hydroxy)methyl]phenyl}thioureas
已经开发了使用两锅法从芳基(2-异硫氰酸根合苯基)甲酮方便地合成N,N-二取代的4 H -3,1-苯并噻嗪-2-胺的方法。因此,用仲胺处理这些异硫氰酸根合酮得到相应的酮硫脲,使其与硼氢化钠或甲基溴化镁反应,得到1,1-二烷基-3- 2- [芳基(羟基)甲基]苯基}硫脲。或分别在一个锅中的1,1-二烷基-3- [2-(1-(芳基-1-羟乙基)苯基]硫脲。这些羟基硫脲前体的氢溴酸介导的环化作用提供了所需的4 H -3,1-苯并噻嗪-2-胺。
Silver-Catalyzed Nucleophilic Addition of β-Dicarbonyls to Isocyano Group: Facile Access to Indolin-3-ol Derivatives
A domino silver-catalyzed intermolecularly nucleophilic addition of β-dicarbonyls to the isocyano group and cyclization of the imidoyl silver sequence was developed for the direct and efficient synthesis of indolin-3-ol derivatives. This domino transformation tolerates a range of readily available o-acyl arylisocyanides and 1,3-dicarbonyls under an operationally simple procedure. Triple roles of silver
Synthesis of 2,4-Dicyanoalkylated Benzoxazines through the Radical-Mediated Cascade Cyclization of Isocyanides with AIBN under Metal- and Additive-Free Conditions
A general and novel method for the radical cascadecyclization of aryl isocyanides with AIBN has been described. This strategy provides straightforward access to various 2,4-dicyanoalkylated benzoxazines in moderate to good yields under metal- and additive-free conditions. The reaction can apply to a gram scale and tolerate diverse functional groups. 2,4-Dicyanoalkylated benzoxazine derivatives feature