Acylation of diethyl (ethoxycarbonyl)fluoromethylphosphonate using magnesium chloride-triethylamine: A facile synthesis of α-fluoro β-keto esters
作者:Dae Young Kim、Dae Yong Rhie、Dong Young Oh
DOI:10.1016/0040-4039(95)02224-4
日期:1996.1
A facile synthesis of α-fluoro β-keto esters, via diacylation reaction of diethyl (ethoxycarbonyl)fluoromethylphosphonate with aromatic carboxylic acid chlorides in the presence of magnesium chloride-triethylamine followed by deacylation, is described.
Iridium-Catalyzed Asymmetric Hydrogenation of Tetrasubstituted α-Fluoro-β-enamino Esters: Efficient Access to Chiral α-Fluoro-β-amino Esters with Two Adjacent Tertiary Stereocenters
An iridium-catalyzed highly efficient asymmetric hydrogenation of challenging tetrasubstituted α-fluoro-β-enamino esters was successfully developed using bisphosphine–thiourea (ZhaoPhos) as the ligand, which prepared a series of chiral α-fluoro-β-amino esters containing two adjacent tertiary stereocenters with high yields and excellent diastereoselectivities/enantioselectivities (73%–99% yields, >25:1
Organic dye photocatalyzed α-oxyamination through irradiation with visible light
作者:Hongjun Liu、Wei Feng、Choon Wee Kee、Yujun Zhao、Dasheng Leow、Yuanhang Pan、Choon-Hong Tan
DOI:10.1039/b924609f
日期:——
Rose Bengal, an organic dye, was used as a visible light photocatalyst to investigate novel α-oxyamination reactions between 1,3-dicarbonyl compounds and a free radical (TEMPO). Compounds that are difficult to obtain such as quaternary fluorinated compounds were synthesized using this method. This visible light photocatalytic reaction can also be performed in water.
Synthesis of a Chiral Quaternary Carbon Center Bearing a Fluorine Atom: Enantio- and Diastereoselective Guanidine-Catalyzed Addition of Fluorocarbon Nucleophiles
The perfect combination: The title reaction provides adducts having quaternarycarboncentersbearing a fluorineatom with high ee and d.r. values (see scheme). The mechanism and origin of stereoselectivity were elucidated by DFT calculations. The bifunctional mode of the guanidine catalysis was demonstrated in the transition states resulting from the DFT results.
Highly Enantioselective Amination Reactions of Fluorinated Keto Esters Catalyzed by Novel Chiral Guanidines Derived from Cinchona Alkaloids
作者:Xiao Han、Fangrui Zhong、Yixin Lu
DOI:10.1002/adsc.201000562
日期:2010.11.2
NovelCinchona alkaloid-derived guanidinescatalyze stereoselective aminations of fluorinatedketoesters, affording products with fluorine-containing quaternary stereogenic centers in excellent yields and with moderate to high enantioselectivities.