Asymmetric Mannich-type Reactions of Fluorinated Ketoesters with Binaphthyl-Modified Thiourea Catalysts
作者:Young-Ku Kang、Sung-Je Yoon、Dae-Young Kim
DOI:10.5012/bkcs.2011.32.4.1195
日期:2011.4.20
enantioselective Mannich-type reaction promoted by chiral binaphthyl-modified bifunctionalorganocatalysts is described. The treatment of α-fluoro-β-ketoesters with N-Boc imines under mild reactionconditions afforded the corresponding β-aminated α-fluoro-β-ketoesters with excellent enantioselectivities (upto 98% ee).Key Words : Mannichreaction, Asymmetric catalysis, Bifunctional organocatalyst, α-Fluoro-β-ketoesters
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.
Asymmetric Mannich Reaction of Fluorinated Ketoesters with a Tryptophan-Derived Bifunctional Thiourea Catalyst
作者:Xiao Han、Jacek Kwiatkowski、Feng Xue、Kuo-Wei Huang、Yixin Lu
DOI:10.1002/anie.200903635
日期:2009.9.28
Fluorinated quaternary stereocenters: A novel bifunctionalcatalyst 1 derived from natural tryptophan promoted the Mannichreaction of α‐fluoro‐β‐ketoesters to afford fluorinated chiral molecules containing vicinal quaternary and tertiary stereogenic centers with exceptional enantioselectivity. An unprecedented α‐fluoro‐β‐lactam was also prepared by this method (see scheme; Boc=tert‐butoxycarbonyl)
available Cinchonaalkaloid as catalyst, the asymmetric allylic alkylation of Morita-Baylis-Hillmancarbonates, with alpha-fluoro-beta-keto esters as nucleophiles, have been successfully developed. A series of important fluorinated adducts, with chiral quaternary carbon centres containing a fluorine atom, was achieved in good yields (up to 93%), with good to excellent enantioselectivities (up to 96%
Enantioselective α-hydrazination of α-fluoro-β-ketoesters catalyzed by chiral nickel complexes
作者:Joo Yang Mang、Dae Gil Kwon、Dae Young Kim
DOI:10.1016/j.jfluchem.2008.11.001
日期:2009.2
The catalytic enantioselective electrophilic α-hydrazination promoted by chiral nickelcomplexes is described. Treatment of α-fluoro-β-ketoesters with azodicarboxylates as electrophilic amination reagents under mild reaction conditions afforded the corresponding α-amino α-fluoro-β-ketoesters with high yields (80–96%) and enantioselectivities (up to 78% ee).