1040185-03-2Relevant academic research and scientific papers
Pyrrole and oligopyrrole synthesis by 1,3-dipolar cycloaddition of azomethine ylides with sulfonyl dipolarophiles
Robles-Machin, Rocio,Lopez-Perez, Ana,Gonzalez-Esguevillas, Maria,Adrio, Javier,Carretero, Juan Carlos
supporting information; experimental part, p. 9864 - 9873 (2010/11/16)
A procedure for the synthesis of functionalized, substituted pyrroles by 1,3-dipolar cycloaddition of azomethine ylides has been developed. This protocol is based on the metal-catalyzed cycloaddition of α-iminoesters with sulfonyl dipolarophiles, followed by the base-promoted elimination of the sulfonyl groups. A wide variety of 2,5-disubstituted and 2,3,5- and 2,4,5trisubstituted pyrroles have been prepared in satisfactory yields from 1,2bis(sulfonyl ethylene), ss-sulfonylenones, and ss- sulfonylacrylates. This method can be applied in an iterative and straightforward manner to the construction of oligopyrroles, from bipyrroles to pentapyrroles. Iterative [n+1] and [n+2] approaches have been devised, the latter involves double 1,3-dipolar cycloaddition from pyrrolylbased bis(iminoesters).
The phenylsulfonyl group as a temporal regiochemical controller in the catalytic asymmetric 1,3-dipolar cycloaddition of azomethine ylides
Lopez-Perez, Ana,Adrio, Javier,Carretero, Juan C.
supporting information; experimental part, p. 340 - 343 (2009/04/14)
(Chemical Equation Presented) Controlling the regioselectivity: The phenylsulfonyl group controlled the regioselectivity in the title reaction to afford pyrrolidine-2,3-dicarboxylates with good regioselectivity and high exo selectivity and enantioselectivity (see scheme). The products are precursors to substituted pyrrolidines and pyrrolines that are not attainable by direct 1,3-dipolar cycloadditions with typical acrylates.
Bis-sulfonyl ethylene as masked acetylene equivalent in catalytic asymmetric [3 + 2] cycloaddition of azomethine ylides
Lopez-Perez, Ana,Adrio, Javier,Carretero, Juan C.
supporting information; experimental part, p. 10084 - 10085 (2009/02/04)
Enantioenriched 3-pyrrolines have been synthesized by highly enantioselective Fesulphos-Cu-catalyzed 1,3-dipolar cycloaddition of azomethine ylides with trans-1,2-bisphenylsulfonyl ethylene, followed by reductive sulfonyl elimination. High levels of reactivity, exoselectivity, and enantioselectivity have been accomplished for a variety of substituted azomethine ylides. This cycloaddition-desulfonylation strategy has been applied as a key step in the enantioselective synthesis of a biologically active C-azanucleoside. Copyright
