Intramolecular allylboration of γ-(ω-formylalkoxy)allylboronates for syntheses of trans- or cis-2-(ethenyl)tetrahydropyran-3-ol and 2-(ethenyl)oxepan-3-ol
作者:Yasunori Yamamoto、Kazunori Kurihara、Akihiko Yamada、Miki Takahashi、Youichi Takahashi、Norio Miyaura
DOI:10.1016/s0040-4020(02)01557-0
日期:2003.1
give 3-alkoxy-1-alkenylboronates 5. The latter gave (E)-3-alkoxyallylboronates (8: (E)-(MeO)2CHCH2(CH2)nCH2OCHCHCH2Bpin, n=1–3) when they were subjected to iridium-catalyzed isomerization of the double bond. The corresponding (Z)-isomers 10 were synthesized by nickel-catalyzed isomerization of 5. Both allylboronates underwent intramolecular allylboration leading to the formation of trans-2-(ethen
将3-烷氧基-1-炔烃4与频哪醇硼烷(HBpin)氢硼化,得到3-烷氧基-1-烯基硼酸酯5。后者在铱催化下生成(E)-3-烷氧基烯丙基硼酸酯(8:(E)-(MeO)2 CHCH 2(CH 2)n CH 2 OCH = CHCH 2 Bpin,n = 1–3)。双键的异构化。通过镍催化的5的异构化合成相应的(Z)异构体10。两种烯丙基硼酸酯都经历了分子内烯丙基硼化作用,导致形成反式-2-(乙烯基)四氢吡喃-3-醇或2-(乙烯基)从oxepan -3-醇8和相应的顺从异构体10中的Yb(OTF)的存在3(20摩尔%)在乙腈水溶液中在90°C下。