Supporting Information
Synthesis, characterization, reactivity of η3-allylPd(L)(X), where X = Cl and L
= imidazolylphosphine and their application in aryl amination reactions
Reji N. Nair1,2*, Christoffel van Niekerk2, Gulin Erdogan2, Douglas B. Grotjahn2*
1
The Scripps Research Institute, Translational Research Institute, 130 Scripps Way, Jupiter,
Florida, 33458
2
Department of Chemistry and Biochemistry, 5500 Campanile Drive, San Diego State
University, San Diego, California, 92182-1030
*corresponding author – dbgrotjahn@mail.sdsu.edu, rnair@scripps.edu
General Experimental Information
Reactions were performed under dry nitrogen, unless otherwise specified, using a
combination of Schlenk line and glovebox techniques. C6D6 and CDCl3 received from
Cambridge Isotope labs were further distilled from CaH2 followed by freeze pump thaw
degassed before use. NMR tube reactions were performed in resealable NMR tubes (J. Young).
Unless otherwise specified, NMR data were measured at 30 °C. Three Varian spectrometers
were used: a 500-MHz INOVA (500 MHz listed below for 1H = 499.940 MHz and 125.7 MHz
for
13
C = 125.718 MHz), a 400-MHz Varian NMR-S (400 MHz listed below for 1H = 399.763
MHz and 100 MHz for
13
C = 100.525 MHz), and a 200 MHz Gemini (31P data at 80.95 MHz)
spectrometer.
1
H and
13
C NMR chemical shifts are reported in ppm downfield from tetramethylsilane
and referenced to solvent resonances (1H NMR: δ 7.27 for CHCl3 and 7.16 for C6D6 and
13
C
NMR: δ 77.2 for CDCl3 and 128.6 for C6D6). 1H NMR signals are given followed by
multiplicity, coupling constants J in Hertz, integration in parentheses. For complex coupling
patterns, the first coupling constant listed corresponds to the first splitting listed, e.g. for (dt, J =
3.2, 7.9, 1H) the doublet exhibits the 3.2-Hz coupling constant.
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P{1H} NMR chemical shifts
were referenced to an external 85% H3PO4 (aq) capillary placed in the solvent. Elemental
analyses were performed at NuMega Laboratories (San Diego). Catalysis screening was done
using a Varian GCMS equipped with a FactorFour Capillary Column (VF-5ms, 25 m X 0.25 mm
internal diameter) incorporating an FID detector. The column was also equipped with a split
junction to enable the flow of injected compounds through a Saturn 2000 Mass Spectrometer,
housed with an ion-trap analyzer.
Synthesis of chloride complexes
General Procedure: A scintillation vial with stir bar, in the glove box, was charged with
allylpalladium chloride dimer (0.3 mmol, 1 equiv) which was dissolved in CHCl3 (3 mL). To this
solution was added phosphine (0.6 mmol, 2 equiv) and the mixture was allowed to stir for 30
min. The solvent was removed under vacuum to obtain pale yellow oil to which was added ether.
The resultant precipitate obtained was filtered, and stored under vacuum to give desired product.
Preparation of 10. Off white solid, 0.122 g, 40 % yield. 1H NMR (CDCl3, 399.9 MHz) δ 7.837.78 (m, 4H), 7.40 (br, 6H), 6.75 (s, 1H), 5.56 (quintet, J = 9.6 Hz, 1H), 4.74 (br s, 1H), 3.763.69 (broad m, 1H), 3.52 (s, 3H), 3.44 (br s, 1H), 2.74 (d, J = 8.0 Hz, 1H), 1.26 ppm (s, 9H); 31P
NMR (CDCl3, 161.8 MHz) δ 4.9 ppm; Anal Calcd for C23H28N2PClPd (505.33): C, 54.66: H,
5.58; N, 5.54. Found: C, 54.02; H, 5.73; N, 5.64.
Preparation of 11. Pale yellow solid, 0.182 g, 67 % yield. 1H NMR (CDCl3, 399.9 MHz) δ 6.65
(d, 1H, J = 2.0 Hz), 5.50-5.40 (m, 1H), 4.74 (t of narrow m, 1H, J = 8.0 Hz), 3.93 (br s, 3H), 3.78
(dd, J = 8.7, 13.5 Hz, 1H), 3.67 (br, 1H), 2.72 (br d, J = 11.5 Hz, 1H), 1.45 (d, 9H, J = 14.8 Hz),
1.43 (sl br d, 9H, J = 14.8 Hz), 1.25 ppm (s, 9H);
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P NMR (CDCl3, 161.8 MHz) δ 38.9 ppm;
Anal Calcd for C19H36N2PClPd (465.35): C, 49.04: H, 7.80; N, 6.02. Found: C, 49.39; H, 8.12;
N, 6.13.
Preparation of 12. Off white solid, 0.260 g, 85 % yield. 1H NMR (CDCl3, 399.9 MHz) – δ 6.70
(s, 1H), 5.48-5.40 (m, 1H), 4.72 (t, J = 6.4 Hz, 1H), 3.84 (s, 3H), 3.66 (dd, J = 9.6, 13.6 Hz, 1H),
3.43 (br s, 1H), 2.93-2.84 (m, 2H), 2.63 (d, J = 11.6 Hz, 1H), 1.27-1.22 (obscured multiplet, 3H),
1.24 (s, 9H), 1.17-1.04 ppm (obscured, 9H);
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P NMR (CDCl3, 161.8 MHz) δ 21.9 ppm; Anal
Calcd for C17H32N2PClPd (437.30): C, 46.69: H, 7.38; N, 6.41. Found: C, 46.43; H, 7.64; N,
6.25.
Preparation of 13. Off white solid, 0.094 g, 87 % yield. 1H NMR (CD2Cl2, 599.6 MHz) – δ 7.68
(br, 4H), 7.52-7.44 (m, 6H), 7.23 (d, J = 6.6 Hz, 2H), 7.10 (s, 1H), 5.66 – 5.59 (m, 1H), 4.73 (br
s, 1H), 3.76 (obscured by singlet at 3.69, 1H), 3.69 (s, 3H), 3.41 (br s, 1H), 2.78 ppm (br s, 1H);
P NMR (CD2Cl2, 161.8 MHz) δ 7.8 ppm; Anal Clcd for C23H28N2PClPd (449.22): C, 54.66: H,
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5.58; N, 5.54. Found: C, 54.02; H, 5.73; N, 5.64.
Preparation of 14. Off white solid, 0.028 g, 74 %. 1H NMR (CD2Cl2, 399.9 MHz) – δ 7.17 (br s,
1H), 7.05 (br s, 1H), 5.54-5.44 (m, 1H), 4.55 (dt, J = 2.0, 6.8 Hz, 1H), 3.98 (br s, 3H), 3.73 (d, J
= 14.0 Hz, 1H), 3.70 (d, J = 13.6 Hz, 1H), 2.74 (d, J = 11.2 Hz, 1H), 1.42 ppm (br d, J = 14.8
Hz, 18H); 31P NMR (CD2Cl2, 161.8 MHz) δ 39.7 ppm; Anal Calcd for C15H28N2PClPd (409.24):
C, 44.02: H, 6.90; N, 6.85; Found: C, 43.88; H, 7.29; N, 6.88.
Preparation of 15. Off white solid, 0.022 g, 65 %. 1H NMR (CDCl3, 399.9 MHz) – δ 7.25 (br s,
1H), 7.07 (br dd, J = 1.2, 2.0 Hz,, 1H), 5.53-5.43 (m, 1H), 4.76 (t, J = 14.4 Hz, 1H), 3.97 (s,
3H), 3.70 (dd, J = 9.6, 13.6 Hz, 1H), 3.47 (br, 1H), 2.96-2.82 (br, 2H), 2.65 (d, J = 12.0 Hz, 1H),
1.31-1.11 ppm (obscured dd, 12H); 31P NMR (CDCl3, 161.8 MHz) δ 24.2 ppm; Anal Calcd for
C13H24N2PClPd (381.19): C, 40.96: H, 6.35; N, 7.35; Found: C, 44.43; H, 7.05; N, 7.28.
Preparation of 16. White solid, 0.234 g, 98 % yield. 1H NMR (CDCl3, 399.9 MHz) – δ 12.90
(br s, 1H), 7.57-7.5 (m, 4H), 7.48-7.36 (m, 6H), 7.30 (br s, 2H), 5.71-5.61 (m, 1H), 4.85 (t, J =
6.8 Hz, 1H), 3.82 (dd, J = 10.0, 14.0 Hz, 1H), 3.21 (br s, 1H), 2.79 ppm (d, J = 12.0 Hz, 1H); 31P
NMR (CDCl3, 161.8 MHz) δ 4.2 ppm; Anal Clcd for C18H18N2PClPd (435.20): C, 49.68: H,
4.17; N, 6.44. Found: C, 48.60; H, 3.86; N, 6.35.
Preparation of 17. 0.201 g, 95 % yield. 1H NMR (CDCl3, 399.9 MHz) – δ 12.96 (br s, 1H), 7.31
(br s, 1H), 7.20 (br s, 1H), 5.57-5.47 (m, 1H), 4.90 (t, J = 8.0 Hz, 1H), 4.28 (t, J = 6.0 Hz, 1H),
3.92 (dd, J = 8.4, 13.4 Hz, 1H), 2.90 (d, J = 12.0 Hz, 1H), 1.39 (d, J = 15.2 Hz, 9H), 1.30 ppm
(d, J = 15.2 Hz, 9H); 31P NMR (CDCl3, 161.8 MHz) δ 48.2 ppm; Anal Clcd for C14H26N2PClPd
(394.22): C, 42.55: H, 6.63; N, 7.07. Found: C, 42.32; H, 6.24; N, 7.08.
Preparation of 18. Off white solid, 0.041 g, 92 % yield. 1H NMR (CDCl3, 399.9 MHz) – δ
12.64 (br s, 1H), 7.28 (br s, 1H), 7.20 (br s, 1H), 5.57-5.47 (m, 1H), 4.86 (t, J = 8.0 Hz, 1H), 3.91
(br d, 1H), 3.83 (dd, J = 8.4, 13.4 Hz, 1H), 2.77 (d, J = 12.0 Hz, 1H), 2.69-2.64 (m, 1H), 2.612.55 (m, 1H), 1.27-1.09 ppm (obscured m, 12H);
31
P NMR (CDCl3, 161.8 MHz) δ 30.6 ppm;
Anal Clcd for C12H22N2PClPd (367.16): C, 39.25: H, 6.04; N, 7.63. Found: C, 38.88; H, 5.42; N,
7.40.
General procedure for ionization of the halide
To a J. Young NMR tube, in the glove box, was added chloride complex (0.05 mmol, 1 equiv)
and dissolved in CDCl3 (1 mL). Initial NMR spectra (1H and 31P) were acquired and to the tube
was added KB(C6F5)4 salt (0.05 mmol, 1 equiv). The contents were allowed to mix well
following which NMR spectra (1H and 31P) for the reaction mixture was acquired.
Preparation of 20. Off white solid, 0.0378 g, 97% yield. 1H NMR (CDCl3, 399.9 MHz) – δ 6.87
(s, 1H), 5.57-5.50 (m, 1H), 4.84 (t, J = 5.6 Hz, 1H), 4.13 (d, J = 6.0 Hz, 1H), 3.82 (s, 3H), 3.70
(dd, J = 10.4, 13.2 Hz, 1H), 2.77 (d, J = 12.8 Hz, 1H), 1.43 (d, J = 16.8 Hz, 9H), 1.33 ppm (d, J
= 16.8 Hz, 9H);
P NMR (CDCl3, 161.8 MHz) δ 50.1 ppm; Anal Calcd for C43H35BF20N2PPd
31
(1108.93): C, 46.62: H, 3.18; N, 2.53. Found: C, 47.20; H, 3.93; N, 3.03.
Preparation of 21. Off white solid (0.0324 g, 98% yield). 1H NMR (CDCl3, 399.9 MHz) – δ
6.85 (s, 1H), 5.57-5.51 (m, 1H), 4.90 (br, 1H), 4.13 (br, 1H), 3.75 (obscured dd, 1H), 3.70 (s,
3H), 2.84 (d, J = 12.4 Hz, 1H), 2.69-2.55 (m, 2H), 1.28 (s, 9H), 1.26-1.05 ppm (m, 12H);
31
P
NMR (CDCl3, 161.8 MHz) δ 28.2 ppm; Anal Clcd for C41H32BF20N2PPd (1080.88): C, 45.56: H,
2.98; N, 2.59. Found: C, 46.16; H, 3.27; N, 2.98.
Preparation of 23. Off white solid, 0.020 g, 97% yield. 1H NMR (CDCl3, 399.9 MHz) – δ 7.23
(t, J = 1.2 Hz, 1H), 7.16 (br s, 1H), 5.54-5.44 (m, 1H), 4.96 (t, J = 5.6 Hz, 1H), 4.18 (d, J = 6.4
Hz, 1H), 3.92 (s, 3H), 3.63 (dd, J = 10.0, 13.2 Hz, 1H), 2.85 (d, J = 12.4 Hz, 1H), 1.47 (d, J =
16.8 Hz, 9H), 1.37 ppm (d, J = 16.4 Hz, 9H); 31P NMR (CDCl3, 161.8 MHz) δ 55.9 ppm; Anal
Clcd for C37H24BF20N2PPd (1024.77): C, 43.37: H, 2.36; N, 2.73. Found: C, 42.91; H, 2.53; N,
2.61.
Exploring the acidity of the NH chloride complexes: synthesis of neutral Pd(II) complexes
General Procedure: To a J. Young NMR tube in the glove box was added chloride complex
(0.05 mmol, 1 eq) and dissolved in C6D6 (1 mL). After acquiring an initial NMR spectrum (1H
and
31
P), added base [NaH (60% in mineral oil) or n-BuLi (1.6 M in hexanes) or KOt-Bu or
NaHMDS] (0.05 mmol, 1 eq) and the contents were allowed to mix well. NMR spectra were
acquired to monitor the results of the reaction.
Deprotonation of 17 with sodium hexamethyldisilazide
To a J. Young tube in the glove box was added 17 (0.0155 g, 0.038 mmol) and dissolved in C6D6
(1 mL). After acquiring an initial NMR spectrum of the complex, to the tube was added
NaHMDS (0.0078 g, 0.040 mmol) and allowed to mix well. The reaction was monitored by
acquiring 1H and 31P NMR spectra which indicated that there was no more identifiable 1H peak
downfield of 12.9 ppm and clean 1H and 31P NMR spectra were obtained. 1H NMR (C6D6, 399.9
MHz) δ 7.78 (s, 1H), 7.58 (s, 1H), 4.62-4.53 (m, 1H), 4.18 (t, J = 6.0 Hz, 1H), 3.38 (d, J = 6.4
Hz, 1H), 2.88 (dd, J = 10.0, 13.2 Hz, 1H), 2.01 (d, J = 11.6 Hz, 1H), 1.30 (d, J = 14.8 Hz, 9H),
1.22 ppm (d, J = 14.8 Hz, 9H); 31P NMR (C6D6, 161.8 MHz) δ 39.0 ppm. However 29 was not
stable and decomposed within 24 h, therefore was not isolated.