Item[KeyEvent["}", Modifiers -> {Command, Shift}],
    FrontEndExecute[{
        FrontEnd`NotebookWrite[FrontEnd`InputNotebook[], "{", After],
        FrontEnd`NotebookWrite[FrontEnd`InputNotebook[], "}", Before]
    }]
    ],

    Item[KeyEvent[")", Modifiers -> {Command, Shift}],
    FrontEndExecute[{
        FrontEnd`NotebookWrite[FrontEnd`InputNotebook[], "(", After],
        FrontEnd`NotebookWrite[FrontEnd`InputNotebook[], ")", Before]
    }]
    ],