there is no exact shortcut like that but there are a number of alternatives. commandoptionM will minimize all windows of the current app. command+H will hide (without minimizing) all windows of the current app and commandoptionH will hide all the apps besides the current one. there is also exposé which lets you make a number of useful shortcuts like one that shows desktop. lastly there are Spaces.
Hold down the option key then click the mouse cursor anywhere on the Desktop, even if it's just a little piece showing in a corner. All appp will hide and you will go right to the Finder or Desktop if you didn't have a finder window open.