A general approach to nitrile- and sulfonyl fluoride-substituted cyclopropanes

Author(s):  
Zai-Wei Zhang ◽  
K. P. Rakesh ◽  
Jing Liu ◽  
Hua-Li Qin ◽  
Haolin Tang

Both cis and trans relative configurations of functionalized cyano cyclopropane bearing sulfonyl fluoride moiety was accessed by Corey–Chaykovsky cyclopropanation reactions. This protocol feathered with mild conditions, good yields and excellent...

1964 ◽  
Vol 42 (5) ◽  
pp. 1123-1129 ◽  
Author(s):  
W. R. Cullen ◽  
N. K. Hota

Arsenobenzene reacts with CF3I to give C6H5As(CF3)2, C6H5As(CF3)I, and C6H5AsI2. C6H5As(CF3)I and AgCl yield C6H5As(CF3)Cl. The compounds CF2=CFX react with (CH3)2As—As(CH3)2 under mild conditions to give 1:1 adducts (CH3)As—CF2CFX—As(CH3)2 (X = CF3, Br). Some (CH3)2As—CF=CF2 is produced when X = Br and is the major product when X = I. When X = F a 1:4 adduct (CH3)2As—(CF2CF2)4—As(CH3)2 is probably formed on ultraviolet irradiation. (CH3)2As—As(CH3)2 reacts with CF3C≡CCF3 to give cis and trans (CH3)2AsC(CF3)=C(CF3)As(CH3)2 and with [Formula: see text] to give (CH3)2AsF and [Formula: see text].


Planta Medica ◽  
2008 ◽  
Vol 74 (03) ◽  
Author(s):  
R Silva ◽  
J Saraiva ◽  
S Albuquerque ◽  
C Curti ◽  
PM Donate ◽  
...  

2007 ◽  
Author(s):  
Fabiano Toledo ◽  
Henrique Marques ◽  
João Comasseto ◽  
Cristiano Raminelli
Keyword(s):  

2019 ◽  
Author(s):  
Raghu Nath Dhital ◽  
keigo nomura ◽  
Yoshinori Sato ◽  
Setsiri Haesuwannakij ◽  
Masahiro Ehara ◽  
...  

Carbon-Fluorine (C-F) bonds are considered the most inert organic functionality and their selective transformation under mild conditions remains challenging. Herein, we report a highly active Pt-Pd nanoalloy as a robust catalyst for the transformation of C-F bonds into C-H bonds at low temperature, a reaction that often required harsh conditions. The alloying of Pt with Pd is crucial to activate C-F bond. The reaction profile kinetics revealed that the major source of hydrogen in the defluorinated product is the alcoholic proton of 2-propanol, and the rate-determining step is the reduction of the metal upon transfer of the <i>beta</i>-H from 2-propanol. DFT calculations elucidated that the key step is the selective oxidative addition of the O-H bond of 2-propanol to a Pd center prior to C-F bond activation at a Pt site, which crucially reduces the activation energy of the C-F bond. Therefore, both Pt and Pd work independently but synergistically to promote the overall reaction


Author(s):  
Birgit Meindl ◽  
Katharina Pfennigbauer ◽  
Berthold Stöger ◽  
Martin Heeney ◽  
Florian Glöcklhofer

Anthracene derivatives have been used for a wide range of applications and many different synthetic methods for their preparation have been developed. However, despite continued synthetic efforts, introducing substituents in some positions has remained difficult. Here we present a method for the synthesis of 2,3,6,7-substituted anthracene derivatives, one of the most challenging anthracene substitution patterns to obtain. The method is exemplified by the preparation of 2,3,6,7-anthracenetetracarbonitrile and employs a newly developed, stable protected 1,2,4,5-benzenetetracarbaldehyde as the precursor. The precursor can be obtained in two scalable synthetic steps from 2,5-dibromoterephthalaldehyde and is converted into the anthracene derivative by a double intermolecular Wittig reaction under very mild conditions followed by a deprotection and intramolecular double ring-closing condensation reaction. Further modification of the precursor is expected to enable the introduction of additional substituents in other positions and may even enable the synthesis of fully substituted anthracene derivatives by the presented approach.<br>


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