opening of the [β,γ] carbon−carbon double bond of the allene is realized. In contrast to these, the reaction of allenylphosphonate (OCH2CMe2CH2O)P(O)(H)C═C═CMe2 possessing a terminal ═CMe2 group with DMAD occurs by both [2 + 2] cycloaddition and ene reaction. While the reaction of ═CH2 terminal allenylphosphonates as well as allenylphosphine oxides with 1,3-diphenylisobenzofuran afforded preferentially
allenylphosphonates的环加成反应[(RO)2 P(O)[(R 1)C═C═CR 2 2 ]与二烷基acetylenedicarboxylates,1,3- diphenylisobenzofuran和
蒽已经研究并与联
烯酸
酯[比较(ETO 2 C)RC═C═CH 2 ]和allenylphosphine
氧化物[PH 2 P(O)(R 1)C═C═CR 2 2 ]在选定的情况下。Allenylphosphonates(RO)2 P(O)(Ar)的C═C═CH 2带有α-芳基的化合物在热活化下优先通过
DMAD /
DEAD进行[4 + 2]环加成反应,但除了预期的1:1(
丙二烯:
DMAD)产物外,该反应还会导致1:2和2 :1之前未报告的产品。当
烯丙基膦酸酯的γ-
碳上存在额外的
乙烯基时[例如,(OCH 2 CMe 2 CH 2 O)P(O)(Ph)C═C═CH(C═CHMe)],[4