Simplify circular generic constraints in C#?

Given the following base classes:

public abstract class PurchaseSystemControllerBase<TController, TViewModel> : IInitializable
    where TController : PurchaseSystemControllerBase<TController, TViewModel>
    where TViewModel : PurchaseSystemViewModelBase<TController, TViewModel> {

    protected TViewModel ViewModel { get; private set; }

    ...
}

public abstract class PurchaseSystemViewModelBase<TController, TViewModel> : ViewModelBase
    where TController : PurchaseSystemControllerBase<TController, TViewModel>
    where TViewModel : PurchaseSystemViewModelBase<TController, TViewModel> {

    protected TController Controller { get; private set; }

    ...
}

Concrete implementations are as follows:

public sealed class PurchaseSystemController : PurchaseSystemControllerBase<PurchaseSystemController, PurchaseSystemViewModel> {
    ...
}

public sealed class PurchaseSystemViewModel : PurchaseSystemViewModelBase<PurchaseSystemController, PurchaseSystemViewModel> {
    ...
}

Is there a way to simplify this so that the following is possible?

public sealed class PurchaseSystemController : PurchaseSystemControllerBase<PurchaseSystemViewModel> {
    ...
}

public sealed class PurchaseSystemViewModel : PurchaseSystemViewModelBase<PurchaseSystemController> {
    ...
}