A thermally induced novel formal [4+2] cycloaddition of cyclobutenones with electron-deficient alkynes under metal-free conditions has been developed for the first time. The reaction can proceed in a highly regioselective manner and provides a straightforward and efficient method for the synthesis of 4-pyridone derivatives from readily available starting materials in a single step.
Copper-catalyzed cascade cyclization reaction of 3-aminocyclobutenones with electron-deficient internal alkynes: synthesis of fully substituted indoles
A novel copper-catalyzed cascade cyclization reaction of 3-aminocyclobutenones with electron-deficient internal alkynes has been developed for the first time. This reaction provides a new and highly efficient method for the synthesis of fullysubstituted indoles by formation of four new bonds and two rings from readily available starting materials in a single step.
fully substituted 2-pyridone 2 and functionalized α-pyrones 3 are synthesized starting from cyclobutenones 1 under a base-promoter in toluene at 80 ℃. This rearrangement is complimentary to the previously reported ringexpansion of cyclobutenones, providing a divergent synthesis of corresponding products from the same precursor 1. In addition, α-pyrones 3 has also been applied to the synthesis of aromatic
Highly efficient synthesis of 3-amino-/alkylthio-cyclobut-2-en-1-ones based on the cyclization of acyl ketene dithioacetals
作者:Yu-Long Zhao、Shao-Chun Yang、Chong-Hui Di、Xiao-Dan Han、Qun Liu
DOI:10.1039/c0cc02470h
日期:——
A new strategy for the highlyefficient one-pot synthesis of 3-amino-/alkylthio-cyclobut-2-en-1-ones based on the cyclization of acyl ketene dithioacetals is disclosed. In addition, the rearrangement of 3-amino-cyclobut-2-en-1-ones to 4-quinolone derivatives is described.