Copper(II)‐catalyzed Domino Reaction of the Acyclic Ketene‐(
<i>S</i>
,
<i>S</i>
)‐Acetals with Diazo Compounds: Convenient Synthesis of Poly‐substituted Thiophenes
the acyclic ketene‐(S,S)‐acetals and diazo compounds has been successfully developed. This reaction proceeds through a sequential formation of electrophilic copper carbenoid, sulfur ylide and subsequent C−S bond coupling and cleavage. Notably, the domino reaction features broad the readily available acyclic ketene‐(S,S)‐acetals scope and provides a new strategy for the synthesis of poly‐substituted