Generation of New Active Lanthanide Species and Their Use in Organic Synthesis

1.Yb-亚胺配合物催化胺的硅氢化反应和亚胺的硅氢化反应。用Yb(η^2-Ph_2CNAr)(HMPa)_n[Yb(HMPA)_n]催化伯胺和仲胺与三苯基硅烷的硅氢化反应，得到了高产率的氨基硅烷。在与二苯基苯基硅烷的反应中，主要生成二氨基硅烷。正烷基胺和仲烷基胺易于硅烷化，而叔烷基胺和芳香胺的反应活性较低。此外，用苯基硅烷和亚胺络合物(At=Ph，C_6H_4F-4)实现了亚胺的硅氢化反应，生成了单氨基硅烷和二氨基硅烷。这两个反应在产物选择性和产率方面是一致的。低价钐促进的酰基膦与两种羰基化合物的三组分偶联：一锅法合成β-羟基膦。酰基膦与两种羰基化合物的三组分偶联反应，得到了低价的β-羟基膦。因此，酰基膦与醛在半催化量的金属钐或SMI_2的存在下反应，以良好的产率得到酰氧基膦。酰氧基膦与醛或酮的第二次偶联反应生成了β-羟基膦酸盐，而不是烯烃。此外，这两个反应可以在一个锅里进行。

1. Dehydrogenative Silylation of Amines and Hydrosilylation of Imines Catalyzed by Ytterbium-Imine Complexes. Dehydrogenative silylation of primary and secondary amines with triphenylsilane was catalyzed by ytterbium-imine complexes, [Yb(η^2-Ph_2CNAr)(hmpa)_n], to give aminosilanes in good yields. In the reaction with diphenyland phenylsilanes, diaminosilanes were formed as major products. While n- and sec-alkylamines were readily silylated, tert-alkylamines and aromatic amines exhibited lower reactivities. Moreover, hydrosilylation of imines has been achieved by using phenylsilane and the imine complexes (At=Ph, C_6H_4F-4), giving rise to mono- and diaminosilanes. The two reactions were in agreement as regards the product selectivities and yields.2. Three-Component Coupling of Acylphosphonates and Two Carbonyl Compounds Promoted by Low-Valent Samariums : One-Pot Synthesis of β-Hydroxyphosphonates. Three-component coupling of acylphosphonates and two carbonyl compounds leading to β-hydroxyphosphonates has been achieved with low-valent samariums. Thus, acylphosphonates reacted with aldehydes in the presence of semi-catalytic amounts of samarium metal or SmI_2 to give acyloxyphosphonates -in good yields. The second coupling reaction of the acyloxyphosphonates with aldehydes or ketones promoted by SmI_2 afforded β-hydroxyphosphonates, instead of olefins. Moreover, these two reactions could be carried out in one pot.