Synthesis of a biphenyl-based axially chiral amino acid as a highly efficient catalyst for the direct asymmetric aldol reaction
作者:Taichi Kano、Osamu Tokuda、Keiji Maruoka
DOI:10.1016/j.tetlet.2006.08.051
日期:2006.10
A biphenyl-based axially chiral amino acid (S)-2 has been designed and synthesized. The new amino acid (S)-2 has been found to be a more efficientcatalyst than (S)-1 in the direct asymmetric aldol reaction of acetone with aldehydes. For instance, the use of only 0.1 mol % of (S)-2 was sufficient to complete the reaction between acetone and 4-nitrobenzaldehyde, giving the corresponding aldol adduct
Practical Synthesis of α,α-Dibromo Esters from Aldehydes
作者:Takayuki Iwata、Kiichi Hatae、Mitsuru Shindo
DOI:10.1021/acs.joc.4c01078
日期:2024.7.19
Herein, we report an efficient and practical method for synthesizing α,α-dibromo esters, which are the precursors of ynolates, through the dibromination of aldehydes followed by oxidative esterification using iodine. Our method was successfully employed in a large-scale synthesis to yield more than 30 g of dibromo esters. These two steps can be performed in a one-pot manner, which makes the method