Table 1.

Results of the in vivo and in vitro ArM‐catalyzed Diels–Alder reaction.

Protein	In vivo[a]		In vitro[b]
	yield [%][c]	ee [%][c]	yield [%][c]	ee [%][c]
SUMO	14±1	0
LmrR	14±4	8±2	22±5	58±6
LmrR_A92E	15±6	17±1	33±10	68±2
LmrR_A92E_V15A	20±3	45±0	52±7	84±3

[a] Cu^II‐Phen (180 μM), E. coli cell suspension (1 mL), 4 (1 mM) and 5 (33 mM) in 20 mM MOPS, 150 mM NaCl at pH 7, reaction time 48 h at 4 °C. [b] Cu^II‐Phen (90 μM), LmrR variant (120 μM), 4 (1 mM) and 5 (33 mM) in 20 mM MOPS, 150 mM NaCl at pH 7, reaction time 48 h at 4 °C. [c] Values for the endo isomer. Values represent the average of independent duplicate experiments, each performed in duplo. Errors are given as standard deviations.