The only situation where this 13 C satellite strategy cannot work is when the strongly coupled protons are bound to the same 13 C spin. This is always the case for strongly coupled geminal protons, but also for 13 C isotopically enriched molecules. It is also conceivable that the 12 Cbound proton and both its 13 C satellites all turn out strongly coupled, each with a separate proton. This situation should be rare, and was not encountered in this work. When it does occur, a possible solution would be to move to a different magnetic field strength, as strong coupling involving 13 C satellites turns out very sensitive to this (see Figure ).