Andrew
You could accomplish this with a microflow that copies the attributes in question to Entity 2 - after created a new object of type Entity 2. This microflow could be called as an event handler on Entity 1, invoked from a page, called from a scheduled event, etc.
This is the scenario I typically use when loading bulk data from a spreadsheet - create Entity A with attributes that match the columns of the spreadsheet and then, once the spreadsheet data is loaded into Entity A, have a microflow that instantiates objects and replicates data as appropriate based on the contents of the spreadsheet data.
Mike