Palladium-catalyzed asymmetric arylation of 2,3-dihydrofuran: 1,8-Bis(dimethylamino)naphthalene as an efficient base
作者:Fumiyuki Ozawa、Akihiko Kubo、Tamio Hayashi
DOI:10.1016/s0040-4039(00)91654-x
日期:1992.3
Reaction of 2,3-dihydrofuran with aryl triflate (1) in the presence of a base and a palladium catalyst, generated in situ from Pd(OAc)2 and (R)-BINAP, gave (R)-2-aryl-2,3-dihydrofuran (2) and a small amount of (S)-2-aryl-2,5-dihydrofuran (3). The enantiomeric purity of major product 2 was strongly affected by the base. 1,8-Bis(dimethylamino)naphthalene (proton sponge) as a highly basic and sterically
在碱和钯催化剂存在下,由Pd(OAc)2和(R)-BINAP原位产生的2,3-二氢呋喃与三氟甲磺酸芳基酯(1)反应,得到(R)-2-芳基-2 ,3-二氢呋喃(2)和少量的(S)-2-芳基-2,5-二氢呋喃(3)。碱强烈影响主要产物2的对映体纯度。1,8-双(二甲基氨基)萘(质子海绵)是一种高度碱性且对空间有要求的胺,对于各种芳基三氟甲磺酸酯,其(R)-2的对映选择性高(> 96-87%ee)。