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.
New phosphine oxide aziridinyl phosphonates as chiral Lewis bases for the Abramov-type phosphonylation of aldehydes
作者:Özdemir Dogan、Muhammet Isci、Muhittin Aygun
DOI:10.1016/j.tetasy.2013.04.005
日期:2013.5
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.