. Author manuscript; available in PMC: 2020 Aug 17.

Published in final edited form as: Org Lett. 2019 Aug 7;21(16):6543–6547. doi: 10.1021/acs.orglett.9b02473

Table 1. Control Studies and Ligand Optimization.

Reaction conditions: Allyl alcohol or carbonate (1.0 equiv, 0.1 mmol), DHP (1.5 equiv, 0.15 mmol), 4CzIPN (3 mol %), Ni catalyst (5 mol %), DMDC (3.0 equiv), and DMF (0.1 M) thoroughly degassed followed by stirring near blue LEDs for 16 h. Overall yields and regioselectivity were determined by GC, and E/Z isomer ratios were determined by NMR.


entry	deviation from standard conditions	yield (%)	E/Z ratio (A:B)
1	R¹ = CO₂Me, R² = i-Pr, No DMDC	83	> 20:1
2	none, R² = i-Pr	66	> 20:1
3	no light, R² = i-Pr	trace	-
4	no photocatalyst, R² = i-Pr	0	-
5	no Ni catalyst, R² = i-Pr	0	-
6	none, R² = Cyclohexyl	85	> 20:1
7	Ni 2, R² = Cyclohexyl	26	7:1
8	Ni 3, R² = Cyclohexyl	66	> 20:1
9	Ni 4, R² = Cyclohexyl	8	E only
10	Ni 5, R² = Cyclohexyl	10	1.3:1
11	Ni 6, R² = Cyclohexyl	73	1:1.2
12	Ni 7, R² = Cyclohexyl	21	2:1