提出了羟基膦酸酯和氨基膦酸酯的绝对构型通过与市售萘普生的双衍生作用的分配。周围的立构碳中心的空间排列和Δδ的符号之间的相关性RS通过简单比较(R)-和(S)-萘普生酯或酰胺衍生物的1 H和31 P NMR光谱,可以确定羟基和氨基膦酸酯的绝对构型。NMR研究对结构多样的萘普生酯和羟基膦酸酯和氨基膦酸酯的酰胺进行了广泛的构象分析(理论计算,低温实验),证明了可以成功使用简化的模型。
New phosphine oxide aziridinyl phosphonates as chiral Lewis bases for the Abramov-type phosphonylation of aldehydes
摘要:
A series of Lewis bases were screened for Abramov-type phosphine additions to aldehydes. A novel phosphine oxide aziridinyl phosphonate POAP-A was found to be better than the others in forming the product in 96% yield and with 42% ee. The absolute configuration of the newly synthesized POAP Lewis bases was determined by single-crystal X-ray analysis. (C) 2013 Elsevier Ltd. All rights reserved.
effective enantioselective hydrophosphonylation of aldehydes. A variety of aromatic, heteroaromatic, condensed-ring, α,β-unsaturated, and aliphatic aldehydes were found to be suitable substrates for the reaction, and the desired α-hydroxy phosphonate were obtained in good to excellent yields (up to 99%) with moderate to good enantioselectivities (up to 87% ee) under mild conditions (at 0 °C). A possible
Bis(oxazoline)-copper catalyzed enantioselective hydrophosphonylation of aldehydes
作者:Tao Deng、Chun Cai
DOI:10.1039/c4ra03269a
日期:——
A highly enantioselective copper-catalyzed hydrophosphonylation of aldehydes in the presence of bis(oxazoline) ligand is presented. The reaction proceeded smoothly under mild conditions. The resulting α-hydroxyphosphonates were obtained with high yields as well as enantioselectivities (up to 98% ee).
transformations using chlorosilane reagents. The p-tolyl-substituted DIOPO (p-tolyl-DIOPO) was most effective for the reductive aldol reaction of chalcone and aldehydes with trichlorosilane, whereas the 2,8-dimethylphenoxaphosphine-derived DIOPO (DMPP-DIOPO) afforded the best enantioselectivity for the phosphonylation of conjugated aldehydes and the chlorinative aldol reaction of an ynone and benzaldehyde.
Chiral N,N'-dioxide-Ytterbium(III) complexes promoted the asymmetric addition of diethyl phosphate to aldehydes, giving the corresponding products with good yields and enantioselectivities. The addition of pyridine favored both reactivity and enantioselectivity. A possible catalytic cycle was proposed to explain the mechanism of the asymmetric hydrophosphonylation of aldehydes. (C) 2010 Elsevier Ltd. All rights reserved.