Experimental identification of aminomethanol (NH₂CH₂OH)-the key intermediate in the Strecker Synthesis

The Strecker Synthesis of (a)chiral α-amino acids from simple organic compounds, such as ammonia (NH₃), aldehydes (RCHO), and hydrogen cyanide (HCN) has been recognized as a viable route to amino acids on primordial earth. However, preparation and isolation of the simplest hemiaminal intermediate - the aminomethanol (NH₂CH₂OH)- formed in the Strecker Synthesis to even the simplest amino acid glycine (H₂NCH₂COOH) has been elusive. Here, we report the identification of aminomethanol prepared in low-temperature methylamine (CH₃NH₂) - oxygen (O₂) ices upon exposure to energetic electrons. Isomer-selective photoionization time-of-flight mass spectrometry (PI-ReTOF-MS) facilitated the gas phase detection of aminomethanol during the temperature program desorption (TPD) phase of the reaction products. The preparation and observation of the key transient aminomethanol changes our perception of the synthetic pathways to amino acids and the unexpected kinetic stability in extreme environments.