Asymmetric Cycloaddition Reactions of Diazoesters with 2-Alkenoic Acid Derivatives Catalyzed by Binaphthyldiimine–Ni(II) complexes
作者:Hiroyuki Suga、Yasuhisa Furihata、Atsushi Sakamoto、Kennosuke Itoh、Yukihisa Okumura、Teruko Tsuchida、Akikazu Kakehi、Toshihide Baba
DOI:10.1021/jo201061f
日期:2011.9.16
(R)-BINIM-4Ph-2QN (ligand C) and Ni(ClO4)2·6H2O) afforded 2-pyrazolines having a methine carbon substituted with an oxazolidinonyl group in moderate ratios (70:30 to 72:28), along with high enantioselectivities (90–92% ee) via 1,3-proton migration. On the basis of the investigations on the counteranions of the Ni(II) complex, the N-substituent of pyrazolidinone, and reaction temperatures, the optimal enantioselectivity
评估了手性联萘二胺(BINIM)-Ni(II)配合物对重氮乙酸乙酯与3-丙烯酰基-2-恶唑烷酮和2-(2-烯酰基)-3-吡唑烷二酮衍生物的不对称对映选择性重氮烷环加成反应的催化活性。在BINIM–Ni(II)络合物(10 mol%;由(R)-BINIM-4Ph-2QN(配体C)和Ni(ClO 4)2 ·6H 2O)通过1,3-质子迁移,以中等比例(70:30至72:28)提供了一个被吡唑啉酮基取代的次甲基碳的2-吡唑啉,以及高对映选择性(90-92%ee)。在对Ni(II)络合物的抗衡阴离子,吡唑烷酮的N-取代基和反应温度进行研究的基础上,获得了2-吡唑啉的最佳对映选择性(97%ee)和比率(85:15)。 (R)-BINIM-4Ph-2QN-Ni(II)((R)-C / Ni(II))存在下2-丙烯酰基-1-苄基-5,5-二甲基-3-吡唑烷酮的反应Ni(BF 4)2 ·6H 2制备的配合物O