Microwave-assisted synthesis of the (E)-α-methylalkenoate framework from multifunctionalized allylic phosphonium salts
作者:Lidiane Meier、Misael Ferreira、Marcus M. Sá
DOI:10.1002/hc.21001
日期:——
A convenient and general microwave-assisted method for the synthesis of stereochemicallydefined α-methylalkenoic acids and esters from allylic phosphonium salts in a basic aqueous medium is described. A selective preparation of acids or esters was dependent on the base (NaOH or NaHCO3) employed in the reaction and could be achieved with good to excellent yields under mild conditions in the absence
Interrupted CuAAC‐Thiolation for the Construction of 1,2,3‐Triazole‐Fused Eight‐Membered Heterocycles from
<i>O</i>
‐/
<i>N</i>
‐Propargyl derived Benzyl Thiosulfonates with Organic Azides
click-sulfenylation of O-/N-propargyl benzyl thiosulfonates with organic azides has been disclosed. The unified CuAAC-thiolation provides a wide range of triazole-fused eight-membered heterocycles in good to high (51–94%) yields under mild reaction conditions. Moreover, a three-component reaction is also achieved involving O-/N-propargyl benzyl thiosulfonates, benzyl bromide, and sodium azide to deliver fused-triazoles
4-(Dimethylamino)pyridine as a catalyst for the lactonization of 4-hydroxy-2-methylenebutanoate esters
作者:Daniel R. Nicponski
DOI:10.1016/j.tetlet.2014.02.024
日期:2014.3
The catalytic action of 4-(dimethylamino)pyridine (DMAP) in lactonizing 4-hydroxy-2-methylenebutanoate esters to 2-methylene-γ-butyrolactones is described. The use of DMAP, which functions as an excellent complement to the more traditional acid-catalyzed lactonization protocol, allows for the synthesis of 2-methylene-γ-butyrolactones containing acid-sensitive groups under essentially neutral conditions
This study presents the synthesis of 14 new 1,4-disubstituted piperazine derivatives from allyl bromides of Baylis–Hillman adduct and 4,4-disubstituted benzhydryl piperazines. All the synthesized compounds were further screened for in vitro ACE inhibitor and antimicrobial activities. Among the synthesized piperazine derivatives, compound 12h showed moderate ACE inhibitor activity as compared to the
Poles apart: The sterically directed [3+2] cycloaddition reactions of dipoles that were generated from Baylis–Hillman bromides with isatin dipolarophiles provided a facile synthetic route to spirodihydrofuran oxindoles and spiroepoxy oxindoles (see scheme). a)–c) Me2S, Cs2CO3, DMF, 15–20 °C, N2, 8 h. EWG: a) CO2Me (Z), b) CO2Me, and c) CN (E).