Hydroformylation is a powerful reaction that has suffered for some negative prejudices related to the use of gaseous H2 and CO. Now it is possible to carry out hydroformylation and different cyclohydrocarbonylations, even on complex substrates, using aqueous formalin as H2 and CO surrogate in few minutes under microwave irradiation. The catalytic system developed by Morimoto (Rh/BINAP for decomposition of formaldehyde and Rh/Xantphos for hydroformylation) is compatible with microwave dielectric heating and with complex substrates containing ligand atoms allowing rapid domino hydroformylation cyclization reactions without using the external supply of gaseous H2 and CO (gas cylinder) and without any particular safety limitation or device.