Table 1.
Entry | Deviation from the standard conditions | Yield (%) | ax:eq |
---|---|---|---|
1 | none | 83 | 4.2:1 |
2 | Pd(OAc)2 instead of Pd(PPh3)4 | 19 | 4.8:1 |
3 | no Pd(PPh3)4 | <2 | - |
4 | Ru(bpy)3(PF6)2 | <2 | - |
5 | Ir(PPy)2(dtbbpy)PF6 | <2 | - |
6 | no Xantphos | 30 | 4.2:1 |
7 | DIPEA instead of K3PO4 | 52 | 4.2:1 |
8 | Cs2CO3 instead of K3PO4 | 67 | 4.2:1 |
9 | no Base | 8 | 4.2:1 |
10 | room temperature | <2 | - |
11 | with air | <2 | - |
12 | no light | <2 | - |
See the Supporting Information (SI) for experimental details. Yields of 3a and axial:equatorial (ax:eq) ratios were determined by 1H NMR analysis using dibromomethane as the internal standard.