One of the most important problems of astrochemistry is to understand how, when and where complex organic and potentially prebiotic molecules are formed - and what is the link between the rich chemistry observed toward some star-forming regions and the emerging Solar System. From an observational point of view, ALMA is revolutionizing the field with its high sensitivity for faint lines, high spectral resolution limiting line confusion, and high angular resolution making it possible to study the structure of young protostars down to scales of their emerging protoplanetary disks.
In this talk, I will present some of the results from a large ALMA survey of the low-mass protostellar binary and astrochemical template source, IRAS 16293-2422. The program, "Protostellar Interferometric Line Survey (PILS)", is more than an order of magnitude more sensitive than previous surveys of chemical complexity and provide images of the inner 25 AU of the gas around each of the young stars. The high sensitivity and spectral resolution of ALMA has allowed us to detect a wealth of species for the first time toward solar-type protostars as well as the ISM in general - for example, molecules of importance for prebiotic chemistry such as peptide-bond containing species and simple sugars. Also, the data show the presence of numerous rare isotopologues of complex organic molecules and other species: the exact measurements of the abundances of these isotopologues shed new light onto the formation of such complex species and provide a chemical link between the embedded protostellar stages and our own Solar System including the composition of comets. Finally, I will discuss some of the issues encountered dealing with these complex datasets with spectra reaching the confusion limit and providing new challenges for laboratory spectroscopy.