3-Stannylcyclobutenediones as Nucleophilic Cyclobutenedione Equivalents. Synthesis of Substituted Cyclobutenediones and Cyclobutenedione Monoacetals and the Beneficial Effect of Catalytic Copper Iodide on the Stille Reaction

Article abstract of DOI:10.1021/jo00306a012

Treatment of 3,4-diisopropoxycyclobutenedione with n-Bu3SnSiMe3/catalytic CN^- furnished 3-isopropoxy-4-(tri-n-butylstannyl)cyclobutenedione in 65 percent yield.This compound cross-coupled with organic iodides attached to sp²- and sp-