Enantioselective NHC‐Catalyzed Redox [2+2] Cycloadditions with Perfluoroketones: A Route to Fluorinated Oxetanes
作者:Alyn T. Davies、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1002/chem.201504256
日期:2015.12.21
carbene (NHC) catalyzedredox formal [2+2] cycloaddition between α‐aroyloxyaldehydes and perfluoroketones, followed by ring‐opening in situ delivers a variety of perfluorinated β‐hydroxycarbonyl compounds in good yield, and excellent diastereo‐ and enantioselectivity. Through a reductive work‐up and subsequent cyclization, this protocol offers access to highly substituted fluorinatedoxetanes in two
Novel and efficient approach to (Z)-4-trifluoroethylidene-1,3-dioxolane derivatives via (trifluoromethyl)ethynylation of ketones and aldehydes
作者:Sung Lan Jeon、Ji Hoon Choi、Jung Ah Cho、Bum Tae Kim、In Howa Jeong
DOI:10.1016/j.jfluchem.2008.05.021
日期:2008.10
the reaction of new stable (trifluoromethyl)ethynylation reagent 1a with TBAF at −15 °C for 10 min, followed by treatment with phenyl perfluoroalkylated ketones at room temperature. The use of aldehydes under the same reaction condition afforded 1,3-dioxolanes 2q–r in good yields. The reaction of 1a with TBAF, followed by treatment with aldehydes or ketones at −15 °C for 10 min and then with trifluoroacetophenone
Preparation of 4-trifluoroethylidene-1,3-dioxolane derivatives via new stable (trifluoromethyl)ethynylation reagent
作者:In Howa Jeong、Sung Lan Jeon、Bum Tae Kim
DOI:10.1016/s0040-4039(03)01779-9
日期:2003.9
Perfluoroalkylated 4-trifluoroethylidene-1,3-dioxolane derivatives 2a–q were prepared in excellent yields from the reaction of newstable (trifluoromethyl)ethynylation reagent 1a with 1.3 equiv. of TBAF at −15°C for 10 min, followed by treatment with 2 equiv. of phenyl perfluoroalkylated ketone derivatives at room temperature. The reaction of 1a with 1.3 equiv. of TBAF, followed by treatment with 1
A Desilylative Approach to Alkyl Substituted C(1)‐Ammonium Enolates: Application in Enantioselective [2+2] Cycloadditions
作者:Yihong Wang、Claire M. Young、Honglei Liu、Will C. Hartley、Max Wienhold、David. B. Cordes、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1002/anie.202208800
日期:2022.9.19
The catalytic generation of unsubstituted and alkylsubstituted C(1)-ammonium enolates from α-silyl-α-alkyl substituted carboxylic acids using the isothiourea HyperBTM has been developed and applied in enantioselective [2+2]-cycloaddition reactions.
Fluoride ion catalyzed isomerization of 2-aryl-F-butenes [1]
作者:Donald J. Burton、James A. Headley
DOI:10.1016/s0022-1139(00)82653-6
日期:1981.10
A kinetic study of the fluorideioncatalyzed isomerization of a series of 2-arylF1-butenes shows the reactions to be pseudo first order in olefin at constant fluorideion concentration. The resultant Hammett plot is non-linear witb a concave downward break near σ=0. A two step mechanism involving formation of a carbanionic intermediate is proposed. A change in the rate limiting step causes the break