季磷盐支载手性咪唑啉酮催化不对称Diels-Alder反应研究

Phosphonium salts supported chiral imidazolidin-4-one:an efficient organic catalyst for the enantioselective Diels-Alder cycloaddition

以(L)-酪氨酸甲酯盐酸盐为手性原料,制备了(S)-5-对羟基苄基-2,2,3-三甲基-4-氧咪唑烷,通过Mitsunobu反应将其支载到可溶性季磷盐载体上,得到新型的支载化可溶性手性催化剂,溶液中均相催化肉桂醛与环戊二烯的不对称Diels-Alder环加成反应,探讨其反应条件及回收重复使用性,发现该手性催化剂进行均相催化反应,具有良好的反应活性及立体选择性,方便分离纯化.

A （L）-tyrosine-derived imidazolidin-4-one was supported on a modified phosphonium salts by the Mitsunobu reaction and converted in situ into a soluble phosphonium salts supported catalyst for the enantioselective Diels-Alder cycloaddition of cinnamaldehyde and 1,3-cyclopentadiene. Discussing the conditions of reaction and recoverability, the result was shown that the chiral catalyst was homogeneous catalysis, with good reactivity and stereoselectivity, and could facilitate the separation and purification.