205692-01-9Relevant academic research and scientific papers
Boron-mediated aldol reaction of carboxylic esters: Complementary anti- and syn-selective asymmetric aldol reactions
Inoue, Tadashi,Liu, Ji-Feng,Buske, Dana C.,Abiko, Atsushi
, p. 5250 - 5256 (2007/10/03)
The boron-mediated aldol reaction of carboxylic esters is described in detail. Contrary to the general belief that carboxylic esters are inert under the condition of the boron enolate formation, propionate esters are enolized with certain combinations of a boron triflate and an amine. More importantly, the stereochemical course of the aldol reaction can be controlled by the judicious selection of the enolization reagents. Treatment of propionate esters with c-Hex2BOTf and triethylamine produces anti-aldol products, and that with Bu2BOTf and diisopropylethylamine gives syn-aldol products selectively after reaction with aldehydes. Complementary anti- and syn-selective asymmetric aldol reactions with structurally related, readily available chiral norephedrine-derived propionate esters are developed.
Attainment of syn-selectivity for boron-mediated asymmetric aldol reactions of carboxylic esters
Liu, Ji-Feng,Abiko, Atsushi,Pei, Zhonghua,Buske, Dana C.,Masamune, Satoru
, p. 1873 - 1876 (2007/10/03)
A new chiral reagent for syn-selective aldol reactions has been developed based on the recent finding that the stereochemistry of the boron-mediated aldol reaction of a carboxylic ester is controlled by the bulkiness of the alcohol moiety of the ester, by the proper choice of reagents, and by the enolization conditions. This readily available, inexpensive reagent has been utilized in studies directed towards the synthesis of the macrolide tedanolide.
