Pinanyldioxy styrylboronic ester (1) was employed for asymmetric 1,3-dipolar cycloaddition with nitrile oxides, optically active Δ2-isoxazolines (3) or 4-hydroxy- Δ2-isoxazolines (4) were obtained. The effect of dif...Pinanyldioxy styrylboronic ester (1) was employed for asymmetric 1,3-dipolar cycloaddition with nitrile oxides, optically active Δ2-isoxazolines (3) or 4-hydroxy- Δ2-isoxazolines (4) were obtained. The effect of different bases on the selectivity of the cycloaddition reaction was studied.展开更多
Summary of main observation and conclusion The stereoselective preparation of vinylboronates via rhodium-catalyzed borylation of E/Z mixtures of vinyl actetates is described, and this method was also extended to synth...Summary of main observation and conclusion The stereoselective preparation of vinylboronates via rhodium-catalyzed borylation of E/Z mixtures of vinyl actetates is described, and this method was also extended to synthesis of vinyldiboronates. These transformations feature high functional group compatibility and mild reaction conditions. Control experiments support a mechanism that involved a Rh-catalyzed borylation-isomerization sequence. The isomerization of (Z)-vinylboronates to (E)-isomers was also demonstrated.展开更多
基金Project (No. 95QA14028) supported by the Star of ScienceTechnology Foundation of Shanghai.
文摘Pinanyldioxy styrylboronic ester (1) was employed for asymmetric 1,3-dipolar cycloaddition with nitrile oxides, optically active Δ2-isoxazolines (3) or 4-hydroxy- Δ2-isoxazolines (4) were obtained. The effect of different bases on the selectivity of the cycloaddition reaction was studied.
基金the National Natural Science Foundation of China(Grant no.21702056)the National Program for Thousand Young Talents of Chinathe Fundamental Research Funds for the CentraI Universities.
文摘Summary of main observation and conclusion The stereoselective preparation of vinylboronates via rhodium-catalyzed borylation of E/Z mixtures of vinyl actetates is described, and this method was also extended to synthesis of vinyldiboronates. These transformations feature high functional group compatibility and mild reaction conditions. Control experiments support a mechanism that involved a Rh-catalyzed borylation-isomerization sequence. The isomerization of (Z)-vinylboronates to (E)-isomers was also demonstrated.
