Biocatalytic One-Pot Synthesis of l-Tyrosine Derivatives from Monosubstituted Benzenes, Pyruvate, and Ammonia

l-Tyrosine derivatives were obtained in >97% ee via a biocatalytic one-pot two-step cascade using substituted benzenes, pyruvate, and NH3 as starting materials. In the first step, monosubstituted arenes were regioselectively hydroxylated in the o-position by monooxygenase P450 BM3 (using O2 as oxidant with NADPH-recycling) to yield the corresponding phenols, which subsequently underwent C–C coupling and simultaneous asymmetric amination with pyruvate and NH3 using tyrosine phenol lyase to furnish l-DOPA surrogates in up to 5.2 g L–1. Instead of analytically pure arenes, crude aromatic gasoline blends containing toluene were used to yield 3-methyl-l-tyrosine in excellent yield (2 g L–1) and >97% ee.