I want the app I deleted from itunes to be deleted from iphone too. Can this be done?
That's how it usually works. What exactly is happening when you sync?
All you need to do is sync your iPhone to your Mac in that situation.
For future reference and removal of apps from your iPhone:
Enter iTunes with either your iPhone attached to your Mac or shown as available via WiFi. Select your iPhone and then select apps from the iTunes menu for the iPhone. Then select "remove" for each app you wish removed from your iPhone. Select "apply", select "sync". It will then ask for confirmation.
Do not remove the apps from your main iTunes apps menu or you will have to re-download them again if you should change your mind later on.
I must apologise - I got it wrong. In fact, iTunes specifically tells you that the app will not be deleted from iOS device, even though you're deleting it from iTunes library:
I suppose it is a safety feature, to protect what is potentially a paid-for app. There's no option, as far as I can see, to circumvent this two-step process.