Figure 4: Substrate scope for decarboxylative alkynylation, alkenylation and arylation of L-aspartic acid and glutamic acid derivatives (1).
From: Visible-light photoredox synthesis of unnatural chiral α-amino acids
(a) Decarboxylative alkynylation of aspartic acid and glutamic acid derivatives (1). (b) Decarboxylative alkenylation of aspartic acid and glutamic acid derivatives (1). (c) Decarboxylative coupling of aspartic acid or glutamic acid derivatives (1) with 2-isocyanobiphenyl. *Reaction conditions: under vacuum and irradiation of visible light, N-Bis(Boc)-Asp(OPht)-OMe (1a) or N-Bis(Boc)-Glu(OPht)-OMe (1b) (0.15 mmol using alkynyl sulfones or 2-isocyanobiphenyl as the partners; 0.10 mmol using alkenyl sulfone as the partner), alkynyl sulfone (4) (0.10 mmol), alkenyl sulfone (6) (0.15 mmol), 2-isocyanobiphenyl (8) (0.10 mmol), [Ru(bpy)3]Cl2 (1.0 μmol), DIPEA (0.25 mmol), HE (0.15 mmol), DCM (1.0 mL), temperature (rt, ~25 °C), time (2–4 h) in a sealed Schlenk tube. †Isolated yield.
