  The search for complex organic molecules (COMs) in the ISM has revealed
chemical species of ever greater complexity. This search relies heavily on the
progress made in the laboratory to characterize the rotational spectra of these
molecules. Observationally, the advent of ALMA with its high angular resolution
and sensitivity has allowed to reduce the spectral confusion and detect
low-abundance molecules that could not be probed before. We present results of
the EMoCA survey conducted with ALMA toward the star-forming region Sgr B2(N).
This spectral line survey aims at deciphering the molecular content of Sgr
B2(N) in order to test the predictions of astrochemical models and gain insight
into the chemical processes at work in the ISM. We report on the tentative
detection of N-methylformamide, on deuterated COMs, and on the detection of a
branched alkyl molecule. Prospects for probing molecular complexity in the ISM
even further are discussed at the end.
