申请人:The Board of Trustees of the University of Illinois
公开号:US20180362513A1
公开(公告)日:2018-12-20
Described herein is the development of an arenophile-mediated, nickel-catalyzed dearomative trans-1,2-carboamination protocol. A range of readily available aromatic compounds was converted to the corresponding dienes using Grignard reagents as nucleophiles. This strategy provided products with exclusive trans-selectivity and high enantioselectivity was observed in case of benzene and naphthalene. The utility of this methodology was showcased by controlled and stereoselective preparation of small, functionalized molecules.
A concise synthesis of (+)-pancratistatin and (+)-7-deoxypancratistatin from benzene using an enantioselective, dearomative carboamination strategy has been achieved. This approach, in combination with the judicious choice of subsequent olefin-type difunctionalization reactions, permits rapid and controlled access to a hexasubstituted core. Finally, minimal use of intermediary steps as well as direct, late stage C-7 hydroxylation provides both natural products in six and seven operations.
The synthesis of aromatic divinylogs and aromatic halogenated vinylogs
作者:K. C. Frisch
DOI:10.1002/pol.1959.1204113829
日期:1959.12
Intermediates for the synthesis of difunctional aromatic vinylogs, p-chloro-allylbenzene was prepared for the first time and p-bromostyrene was made by methods different from those reported previously for this material. The usefulness of anhydrous cobaltous chloride for the activation of vinyl bromide in the reaction with aromatic Grignard compounds was demonstrated in the synthesis of p-allyl- and p-bromostyrene
作者:Lucas W. Hernandez、Ulrich Klöckner、Jola Pospech、Lilian Hauss、David Sarlah
DOI:10.1021/jacs.8b01726
日期:2018.4.4
We describe the development of an arenophile-mediated, nickel-catalyzed dearomative trans-1,2-carboamination protocol. A range of readily available aromatic compounds was converted to the corresponding dienes using Grignard reagents as nucleophiles. This strategy provided products with exclusive trans-selectivity and high enantioselectivity was observed in case of benzene and naphthalene. The utility
Facile synthesis of a series of liquid crystalline 2-(4'-alkylphenyl)-5-cyanopyridines
申请人:Chia Win-Long
公开号:US20080146813A1
公开(公告)日:2008-06-19
The invention relates to a facile synthesis of a series of 2-(4′-alkylphenyl)-5-cyanopyridine liquid crystal compounds which are represented by the following formula (I):
wherein C
n
is a linear alkyl having 1-12 carbon atoms. The synthesis of the liquid crystalline 2-(4′-alkylphenyl)-5-cyanopyridine is completed in a two-step reaction. First, a Grignard reagent (such as 4-alkylphenylmagnesium bromide) is added to a 3-cyanopyridinium salt (such as N-phenyloxycarbonyl-3-cyanopyridinium chloride) to get a 1,2-dihydropyridine. Then the 1,2-dihydropyridine is oxidized with o-chloronil to obtain the 2-(4′-alkylphenyl)-5-cyanopyridine.