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. Author manuscript; available in PMC: 2009 Sep 1.
Published in final edited form as: J Am Chem Soc. 2005 Jun 22;127(24):8644–8651. doi: 10.1021/ja0430346

Table 3. Effect of Chelating Phosphine Ligands.

Entry Ligand Bite Angle(c) 2 3a 4 5a
1 dppm 7329a 12 11 51 26
2 dppe-p-CF3 86(d) 20 25 28 27
3(g) dppe 8629a 5 7 63 25
4 dppe-p-OMe 86(d) 3 4 69 24
5 dpp-benzene 87(e),29b 87 3 7 4
6 dcpe 8729c 11 4 19 66
7 dppp 9129a 31 58 8 3
8 BINAP 9329d 32 9 37 22
9(g) dppb 9429e 4 10 56 30
10 dppf 9929f 27 42 12 19
11 dppf-i-Pr 10329g 13 12 0 75
12 dpe-phos 104(f),29h 19 27 37 17
13 xantphos 108(f),29h 54 46 0 0
(a)

Conditions: 1.0 equiv 1a, 2.0 equiv 4-bromotoluene, 1.2 equiv NaOtBu, 1 mol % Pd2(dba)3, 2 mol % ligand, toluene (0.25 M), 110 °C. The product ratios refer to GC ratios of products 2-5 that have been corrected for GC response factor. All reactions proceed to completion unless otherwise noted.

(b)

The reaction was conducted with 1.4 equiv 4-bromotoluene.

(c)

Bite angles were obtained from crystal structures of bis(phosphine)PdCl2 complexes.

(d)

The bite angle was estimated based on analogy to dppe.

(e)

The bite angle was obtained from a crystal structure of the bis(phosphine)PdBr2 complex.

(f)

The bite angle was obtained from a crystal structure of the bis(phosphine)Pd(1,1-dimethylallyl)tetrafluoroborate complex.

(g)

Approximately 3% of an imine side product derived from substrate oxidation was detected by GC and GC/MS analysis of the crude reaction mixture.