previously described Lewis acidic POMs are reported. Competitive reactions between imines and aldehydes or between various imines demonstrated that fine tuning of the reactivity could be reached by varying the metal atom incorporated into the polyanionic framework. A series of experiments that employed pyridine derivatives allowed us to distinguish between the Lewis and induced Brønsted acidity of the POMs
报道了新的有机可溶性路易斯酸性多金属氧酸盐(POMs)的制备。这些络合物是通过将Zr,Sc和Y原子掺入相应的单腔道森[P 2 W 17 O 61 ] 10-和Keggin [PW 11 O 39 ] 7-多氧钨酸盐制备的。评价了这些化合物对C的催化活性。Diels-Alder,Mannich和Mukaiyama型反应中的C键形成。报道了与先前描述的路易斯酸性POM的比较。亚胺和醛之间或各种亚胺之间的竞争性反应表明,通过改变掺入聚阴离子骨架中的金属原子,可以实现反应性的精细调节。一系列使用吡啶衍生物的实验使我们能够区分POM的Lewis酸度和诱导的Brønsted酸度。这些催化剂以路易斯酸性方式活化亚胺,而醛通过间接布朗斯台德催化剂活化。
Asymmetric synthesis catalyst based on chiral brsnsted acid and method of asymmetric synthesis with the catalyst
申请人:Akiyama Takahiko
公开号:US20060276329A1
公开(公告)日:2006-12-07
A compound usable as an asymmetric synthesis catalyst which can be easily synthesized without using any metal such as a lanthanoid group element; a method of asymmetric synthesis with the compound; and a chiral compound obtained by the asymmetric synthesis method. A Broensted acid is used as a catalyst in asymmetric synthesis, the chiral Broensted acid being represented by formula (1) below or formula (3) below. The asymmetric synthesis method employs the catalyst. Asymmetric synthesis with the catalyst gives a chiral compound.