Ogata Akitoshi, Nemoto Masami, Kobayashi Kenji, Tsubouchi Akira, Takeda Takeshi
Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan.
Chemistry. 2007;13(4):1320-5. doi: 10.1002/chem.200601326.
Titanocene(II)-promoted cross coupling of alkynyl- and (Z)-alkenyl sulfones affords alpha-(phenylsulfonyl)alkenyltitanium species. Further treatment of these species with the titanocene(II) reagent generates titanium vinylvinylidene complexes, which react with carbonyl compounds in one pot to produce substituted vinylallenes with complete stereoselectivity. By using alpha,beta-unsaturated ketones, 1,3,4,6-tetraenes are also obtained stereoselectively.
二茂钛（II）促进的炔基砜和（Z）-烯基砜的交叉偶联反应生成α-（苯磺酰基）烯基钛物种。用二茂钛（II）试剂进一步处理这些物种会生成钛乙烯基亚乙烯基络合物，该络合物可与羰基化合物一锅反应，以完全立体选择性地生成取代的乙烯基丙二烯。通过使用α，β-不饱和酮，还能立体选择性地得到1,3,4,6-四烯。
