Logic Masters Deutschland e.V.

This is the third puzzle in my series of 6x6 global entropy puzzles. You can try the previous two here:
1. Double Entropy
2. Entropic Arrows


RULES:

Normal 6x6 sudoku rules apply: Place the digits 1-6 once each in every row, column and 2x3 box.

Global entropy: Each 2x2 area in the grid must contain at least one digit from each of the three entropic sets: {1,2}, {3,4}, {5,6}.

Killer: Digits in a cage may not repeat and sum to the total given.