Transition Metal-Free Synthesis of Halobenzo[b]furans from O-Aryl Carbamates via o-Lithiation Reactions
作者:Claudia Feberero、Cintia Virumbrales、Carlos Sedano、Lorena Renedo、Samuel Suárez-Pantiga、Roberto Sanz
DOI:10.3390/molecules27020525
日期:——
A straightforward and transition metal-free one-pot protocol to synthesize halobenzo[b]furans has been developed employing simple and easily available starting materials such as O-aryl carbamates and alkynylsulfones. The fine-tuning of the different steps involved was key to achieving a successful one-pot procedure. Initially, a directed ortho-lithiation process, which uses the carbamate as the directed
使用简单易得的起始材料(如 O-芳基氨基甲酸酯和炔基砜)开发了一种直接且不含过渡金属的一锅法合成卤代苯并 [b] 呋喃。所涉及的不同步骤的微调是成功实现一锅法的关键。最初,使用氨基甲酸酯作为定向金属化基团的定向邻位锂化过程对于通过邻锂化氨基甲酸酯的直接炔基化提供 O-2-炔基芳基 N,N-二乙基氨基甲酸酯至关重要,芳基磺酰基炔烃作为亲电试剂。通过涉及在常规加热或微波照射下原位氨基甲酸酯碱水解的策略,成功地完成了生成的邻炔基氨基甲酸酯的环化,再加上随后的杂环化步骤,提供所需的苯并[b]呋喃。已经合成了多种新的卤代苯并[b]呋喃,并通过进一步转化证明了它们的实用性。