Evaluation of organophoto-catalytic activity^a.

Entry	Pcat 1	λ b (nm)	Yieldc (%)	drd	ee (%)e,f
1a,c	1a	365	60	1 : 2	(−) 92/93e
2a	1b	405	—	—	—
3a,c	1c	405	31	1 : 2.5	(−) 37/43
4a	1d	405	72	1 : 1.5	(−) 97/97e
5d	1e	405	63	1 : 1.3	0/0

^aReaction conditions: 14a (0.1 mmol), 15a (0.15 mmol) and EtSH (0.25 mmol) and 1 (0.01 mmol) in 1 mL of CH₂Cl₂ at −40 °C for 20 hours; then 1H-pyrazole (0.3 mmol), LED, rt under O₂ atmosphere for 16 h.

^bWavelength of irradiation.

^cIsolated yield after column chromatography.

^ddr was determined by ¹H-NMR analysis and anti-diastereoselectivity assumed by analogy with our previous work.

^eEnantiomeric excess was determined by HPLC analysis on chiral stationary phase.

^f(+) refers to absolute S configuration, (−) refers to R configuration, assigned based on our previous work (ref. 17).