Tandem regioselective synthesis of tetrazoles and related heterocycles using iodine
作者:Ramesh Yella、Nilufa Khatun、Saroj Kumar Rout、Bhisma K. Patel
DOI:10.1039/c0ob01007c
日期:——
carbodiimides). The in situ generated heterocumulene on subsequent treatment with sodium azide at room temperature gave corresponding tetrazoles. The product regioselectivity for unsymmetrical 1,3-disubstituted thioureas was found to be correlated with the basicities (pKa's) of the parent amines attached to the thiourea. Aryl-sec-alkyl unsymmetrical thioureas gave thioamido guanidino products rather than the 5-aminotetrazoles
已经开发了一种一锅串联方法,用于从异硫氰酸芳基酯合成四唑化合物。异硫氰酸芳基酯与氨,和芳基胺(R-NH 2)提供了单,1,3-二取代的对称和不对称的硫脲,这些硫脲在用分子碘(I 2)脱硫后,形成了相应的杂亚异丙基苯(氰胺或碳二亚胺)。在原位上与后续处理中产生的杂累叠氮化钠在室温下得到相应的四唑。对于非对称1,3-二取代的硫脲产物区域选择性被发现与所述碱度(对相关联ķ一个附接至硫脲母体胺的)。芳基-仲-烷基不对称硫脲得到的是硫酰胺基胍基产物,而不是由HgCl 2介导的反应产生的5-氨基四唑。双-thioureas从芳基异硫氰酸酯和衍生肼 仅给予噻二唑。