Binding IsEnabled for MenuItem

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data-binding

Hello everyone.
I wrote next code of XAML:

<ToggleButton x:Name="toggleButton" Content="Toggle"/>

<Button Content="Button" Height="62" Name="button1" Width="113" IsEnabled="{Binding IsChecked, ElementName=toggleButton}"/>

<DataGrid AutoGenerateColumns="False" Height="71" Name="dataGrid1" Width="175">
    <DataGrid.ContextMenu>
        <ContextMenu>
            <MenuItem Header="menuItem1" IsEnabled="{Binding IsChecked, ElementName=toggleButton}" Name="menuItem1" />
        </ContextMenu>
    </DataGrid.ContextMenu>
    <DataGrid.Columns>
        <DataGridTextColumn Header="Column1" />
        <DataGridTextColumn Header="Column2" />
        <DataGridTextColumn Header="Column3" />
    </DataGrid.Columns>

Binding for button1 work fine, but databinding for menuItem1 doesn't work. Can you tell me where I am wrong and how can I use databinding for MenuItem?