Tebbe's reagent 、 2-ethylpent-1-en-3-yne 在
N(C2H5)3 or pyridine or 4-(dimethylamino)pyridine 作用下,
以
苯 为溶剂,
生成 、 、
参考文献:
名称:
金属环丁烯-金属环丁二烯(乙烯基碳烯配合物)的相互转化:钛环丁烯的开环
摘要:
Preparation of titanacyclobutenes bearing vinyl substituents on the alpha-position of the metallacyclobutene ring is reported. Ring opening of such titanacyclobutenes is anticipated to afford divinylcarbene complexes (or their biradical analogs); reclosure of the titanacyclobutene ring then can result in either regeneration of the starting complex or in the formation of an isomeric titanacyclobutene. Experimentally, the instantaneous isomerization observed is consistent with rapid, reversible ring opening.
.alpha.-Haloalkanesulfonyl bromides in organic synthesis. 5. Versatile reagents for the synthesis of conjugated polyenes, enones, and 1,3-oxathiole 1,1-dioxides