The abiotic synthesis of peptides has been limited in short amino acid length and is favored in highly alkaline conditions where RNAs are unstable. This study demonstrates that boric acid enables amino acid polymerization at acidic and near-neutral pH levels through simple heating experiments. This boron-assisted polypeptide synthesis occurs in prebiotically plausible environments, potentially allowing for simultaneous RNA formation and protein-RNA interactions, crucial steps in the origin of life.