Synthesis of C2-symmetric bisphosphine ligands from tartaric acid, and their performance in the Pd-Catalyzed asymmetric o-allylation of a phenol

Article abstract of DOI:10.1002/ejoc.201402326

Starting from tartaric acid derived chiral diols or dicarboxylic acid dichlorides with either a 2,2-dimethyl-1,3-dioxolane (Taddol) or a 2,3-dimethoxy-2,3-dimethyl-1,4-dioxane (Tatrol) core structure, and BH ₃-protected ortho-phosphanyl phenols, a set of fourteen new C ₂-symmetric diphosphine ligands was synthesized. In addition, three related ligands were obtained from ortho-diphenylphosphino-anilines. The fully characterized ligands were then tested in the Pd-catalyzed enantioselective O-allylation of 4-methoxyphenol using crotyl methyl carbonate as a reagent. In addition, a pseudo-intramolecular variant of the reaction, using crotyl 4-methoxyphenyl carbonate as a substrate, was studied. The so-called Trost ligand was used as a reference. Although the Trost ligand (3 mol-%) gave up to 84% ee, one of the new ligands showed higher activity (50% ee with 0.075 mol-%). Copyright

Full text of DOI:10.1002/ejoc.201402326

Eur. J. Org. Chem. 2014 · © WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, 2014 · ISSN 1099–0690
SUPPORTING INFORMATION
DOI: 10.1002/ejoc.201402326
Title: Synthesis of C2-Symmetric Bisphosphine Ligands from Tartaric Acid, and Their Performance in the Pd-
Catalyzed Asymmetric O-Allylation of a Phenol
Author(s): Mehmet Dindaroğlu, Sema Akyol Dinçer, Hans-Günther Schmalz*

1. Test reactions
2. Synthesis of tartaric acid-derived chiral building blocks
3. Synthesis of borane-protected phosphanyl phenols
4. Analytical data of borane-protected ether-bridged bisphosphine ligand precursors
5. Synthesis of the carbonate substrates
6. 1H and 13C NMR spectra of the carbonate substrates
7. 1H and 13C NMR spectra of 1-(but-3-en-2-yloxy)-4-methoxybenzene
8. 1H and 13C of ether-, ester-, amide- and amine-bridged bisphosphine ligands
9. 31P NMR spectra of selected ligands
Submitted to the European Journal of Organic Chemistry
1

1. Test reactions
Table S-4. Results of the decarboxylative O-allylation of carbonate 31 according to Scheme 6-B using ligand 23a
in different solvents. Ligand 23a (0.075 mol%); Pd2(dba)3·CHCl3 (0.025 mol%).
Solvent
T [°C]
Time [h]
Conversion [%]
32:33 [%]
ee [%]
THF
THF
Toluene
Toluene
0
r.t.
0
24
24
24
24
20
60
10
25
80:20
80:20
85:15
82:18
32
23
38
30
r.t.
Table S-5. Results of the decarboxylative O-allylation of carbonate 31 according to Scheme 6-B using ether-bridged
bisphosphine ligands.
Ligand [mol%]
Pd2(dba)3·CHCl3
[mol%]
0.25
0.05
0.1
0.05
0.05
0.025
0.25
0.05
0.1
0.05
0.05
0.025
0.05
T [°C]
Time Conversion [%]
[h]
32:33 [%]
ee [%]
23c [0.75]
23c [0.15]
23e [0.3]
0
r.t.
0
0
0
0
0
r.t.
0
0
4
36
4
24
24
24
4
36
4
10
6
100
100
100
100
100
100
100
100
100
100
85
85:15
95:5
32
46
26
30
4
71:29
75:25
87:13
86:14
95:5
23e [0.15]
23b [0.15]
23b [0.075]
23d [0.75]
23d [0.15]
23f [0.3]
23f [0.15]
23i [0.15]
23i [0.075]
23j [0.15]
23j [0.075]
10
5
95:5
20
10
12
10
14
7
67:33
70:30
80:20
80:20
70:30
85:15
r.t.
r.t.
r.t.
r.t.
20
6
100
70
0.025
20
30
8
Table S-6. Results of the decarboxylative O-allylation of carbonate 31 according to Scheme 6-B using ester-bridged
bisphosphine ligands.
Ligand [mol%]
Pd2(dba)3·CHCl3
[mol%]
T [°C]
Time Conversion [%]
[h]
32:33 [%]
ee [%]
25a [3]
1
0.1
0
0
0
r.t.
0
0
r.t.
0
0
2
3
24
24
4
72
72
4
100
100
50
0
100
20
26
100
20
85:15
91:9
92:8
---
83:17
99:1
99:1
80:20
80:20
rac
24
30
---
rac
26
26
rac
10
25a [0.3]
25a [0.15]
25a [0.075]
25c [3]
25c [0.075]
25c [0.075]
25b [3]
0.05
0.025
1
0.025
0.025
1
25b [0.075]
0.025
72
Table S-7. Results of the decarboxylative O-allylation of carbonate 31 according to Scheme 6-B using amide- and
amine-bridged bisphosphine ligands.
Ligand [mol%]
Pd2(dba)3·CHCl3
T [°C]
Time Conversion [%]
[h]
32:33 [%]
ee [%]
[mol%]
28a [3]
1
r.t.
0
0
r.t.
r.t.
r.t.
1
4
24
24
24
24
100
100
0
0
11
15
83:17
85:15
---
---
99:1
99:1
8
4
---
---
24
25
28a [1.5]
28a [0.15]
27a [0.15]
27b [3]
0.5
0.05
0.05
1
27b [6]
2
Submitted to the European Journal of Organic Chemistry
2

2. Synthesis of tartaric acid derived chiral building blocks
(4R,5R)-2,2-Dimethyl-1,3-dioxolane-4,5-dicarboxylic acid dimethyl ester (14)
Under an argon atmosphere 23.43 g (0.132 mol, 1.0 equiv) of (L)-(+)-dimethyl tartrate 13 were dissolved in 200 ml of acetone.
To the reaction solution was added under water bath cooling 10 ml (0.079 mol, 0.6 equiv) of boron trifluoride diethyl etherate
over 30 min. The solution was then stirred for 24 h at room temperature. For workup, the reaction mixture was poured into
1 L of saturated NaHCO3-solution. The aqueous layer was extracted three times with 250 ml of ethyl acetate. The combined
organic layers were washed twice with 250 ml of water, dried over MgSO4 and the solvent was removed under reduced
pressure. The yellow crude product was purified by distillation at 95 °C using an oil pump vacuum to obtain 20.71 g
(0.095 mol, 72%) of 14 as an oil.
1
Rf = 0.3 (cyclohexane:EtOAc / 5:1), H NMR (300 MHz, CDCl3): δ = 4.76 (s, 2H, H3), 3.77 (s, 6H,
H5), 1.44 (s, 6H, H1). 13C NMR (APT, 75 MHz, CDCl3): δ = 169.9 (C4), 113.7 (C2), 76.8 (C3),
52.7 (C5), 26.2 (C1). IR (ATR): 2993 (w), 2960 (w), 1736 (s), 1437 (m), 1373 (m), 1204 (s), 1104 (s),
1006 (m), 855 (m), 746 (w) cm-1. GC-MS (EI): m/z (%) = 203 (100), 175 (3), 159 (28), 141 (19), 133
(8), 113 (11), 101 (20), 85 (19), 73 (40), 59 (33), 43 (87). [α]λ (20 °C, CHCl3, c = 2.4): [α]589 = -45.3°,
[α]546 = -53.6°, [α]405 = -105.7°, [α]365 = -136.2°
(2R,3R,5R,6R)-5,6-Dimethoxy-5,6-dimethyl-1,4-dioxane-2,3-dicarboxylic acid dimethyl ester (18)
Under an argon atmosphere 17.82 g (100 mmol, 1.0 equiv) of (L)-(+)-dimethyl tartrate (13) and 1.16 g (5 mmol, 0.05 equiv)
of (DL)-10-camphor sulfonic acid were dissolved in 100 ml dry methanol. To this solution was added 10.33 ml (120 mmol,
1.2 equiv) of 2,3-butanedione and 44 ml (400 mmol, 4.0 equiv) of trimethyl orthoformate. The reaction mixture was then
heated under reflux for 24 h. After cooling to room temperature, 16 g of NaHCO3 were added to the dark red solution and
stirring was continued for 15 min. The mixture was filtered and concentrated under reduced pressure by rotary evaporation.
The crude product was purified by flash column chromatography (cyclohexane/EtOAc, 5:1) to give product 18 (25.1 g,
86 mmol, 86%) as a white solid.
1
Rf = 0.25 (cyclohexane:EtOAc / 5:1), m.p. = 108 °C, H NMR (300 MHz, CDCl3): δ = 4.51 (s, 2H,
H3), 3.74 (s, 6H, H5), 3.30 (s, 6H, H6), 1.33 (s, 6H, H1). 13C NMR (APT, 75 MHz, CDCl3): δ =
168.4 (C4), 99.2 (C2), 68.7 (C3), 52.5 (C5), 48.4 (C6), 17.3 (C1). IR (ATR): 2992 (w), 2951 (w),
2835 (w), 1742 (s), 1437 (m), 1377 (m), 1359 (m), 1285 (m), 1200 (s), 1172 (s), 1110 (s), 1032 (s),
950 (w), 886 (m), 853 (m), 809 (w), 773 (w), 741 (w) cm-1. GC-MS (EI): m/z (%) = 261 (9), 229 (4),
144 (23), 113 (100), 73 (43), 59 (23). HRMS (ESI): calcd. for C12H20O8Na [M+Na]+ 315.1050;
found 315.1046. [α]λ (20 °C, CHCl3, c = 1.0): [α]589 = -140.6°, [α]546 = -166.0°, [α]405 = -324.7°,
[α]365 = -413.8°.
(4S,5S)-4,5-Bis(hydroxymethyl)-2,2-dimethyl-1,3-dioxolane (15)
Submitted to the European Journal of Organic Chemistry
3

Under an argon atmosphere 9.1 g (0.24 mol, 4 equiv) of LiAlH4 were suspended in 120 ml of dry THF and cooled to 0 °C.
13.1 g (0.06 mol, 1 equiv) of 14 were dissolved in 100 ml of dry THF and added dropwise to the suspension. The mixture was
heated under reflux for 2 h. After cooling to room temperature, the mixture was carefully quenched with 40 ml of water and
20 ml of 15% w/w NaOH. The resulting suspension was stirred for 2 h at room temperature, which changed the color from
gray to white. The solvent was removed under reduced pressure, the white solid was transferred to a Soxhlet extractor and
heated to reflux for 24 h with dry THF. The solvent of Soxhlet-extraction was dried over MgSO4 and removed under reduced
pressure. The resulting yellow oil was purified by flash column chromatography (cyclohexane/EtOAc, 1:2) to give the chiral
diol 15 (9.57 g, 59 mmol, 98%) as a colorless oil.
1
Rf = 0.2 (cyclohexane:EtOAc / 1:2), H NMR (300 MHz, CDCl3): δ = 3.92 (t, 2H, H3), 3.74-3.64 (m,
4H, H4), 3.01 (s, 2H, OH), 1.37 (s, 6H, H1). 13C NMR (APT, 75 MHz, CDCl3): δ = 109.2 (C2), 78.2
(C3), 62.0 (C4), 26.9 (C1). IR (ATR): 3377 (br), 2986 (m), 2933 (m), 2880 (m), 2246 (w), 1636 (w),
1450 (m), 1371 (s), 1214 (s), 1164 (s), 1046 (s), 909 (s), 842 (s), 728 (s) cm-1. GC-MS (EI): m/z (%) =
147 (34), 131 (22), 113 (3), 101 (5), 87 (8), 69 (20), 59 (100). HRMS (ESI): calcd. for C7H14O4Na [M+Na]+ 185.0784; found
185.0785. [α]λ (20 °C, CHCl3, c = 1.5): [α]589 = +0.8°, [α]546 = +1.4°, [α]405 = +6.6°, [α]365 = +11.1°.
(4R,5R)-Disodium-2,2-dimethyl-1,3-dioxolane-4,5-dicarboxylate (16)
In a 100 ml two-necked flask 3.0 g (14 mmol, 1 equiv) of dioxolane 14 were dissolved in 30 ml of EtOH and heated to 70 °C.
1.2 g (31 mmol, 2.2 equiv) of NaOH were dissolved in 5 ml of water, diluted with 25 ml of EtOH and the resulting solution
was added dropwise to the reaction mixture. The mixture was heated under reflux for 15 min and the solvent was removed
under reduced pressure. The white solid was washed three times with 50 ml of cold EtOH and dried under vacuum to give
compound 16 (3.0 g, 13 mmol, 93%) as a white solid.
O
1
m.p. = 300-325 °C (decomposition), H NMR (300 MHz, CDCl3): δ = 4.51 (s, 2H, H3), 1.48 (s, 6H,
3
1
H1). 13C NMR (APT, 75 MHz, CDCl3): δ = 177.2 (C4), 111.7 (C2), 79.4 (C3), 25.6 (C1). IR (ATR):
1597 (s), 1406 (m), 1375 (m), 1315 (w), 1263 (w), 1209 (m), 1161 (w), 1068 (m), 974 (w), 871 (m),
821 (w), 783 (w), 742 (m) cm-1.
O
O
4
NaO
NaO
2
O
(4R,5R)-2,2-Dimethyl-1,3-dioxolane-4,5-dicarboxyl dichloride (17)
Under an argon atmosphere 2.34 g (10 mmol, 1 equiv) of compound 16 were suspended in 20 ml of dry benzene and the
resulting suspension was cooled to 0 °C. 5.15 ml (60 mmol, 6 equiv) of oxalyl chloride were slowly added to the suspension,
the resulting mixture was heated under reflux for 1 h and then stirred over night at room temperature. The solvent was
removed under reduced pressure and the resulting solid was suspended in 100 ml CH2Cl2. The suspension was stirred at room
temperature for 1 h, before the mixture was filtered through a glass frit and washed with CH2Cl2. The solvent was removed
under reduced pressure and the resulting light brown solid was dried under vacuum, to give 1.93 g (8.5 mmol, 85%) of 17.
1
m.p. = 42 °C, H NMR (300 MHz, CDCl3): δ = 5.18 (s, 2H, H3), 1.54 (s, 6H, H1). 13C NMR (APT,
75 MHz, CDCl3): δ = 172.1 (C4), 117.4 (C2), 83.6 (C3), 26.8 (C1). IR (ATR): 3501 (br, w), 2991 (w),
2941 (w), 2546 (br, w), 1731 (s), 1377 (m), 1213 (s), 1107 (s), 973 (w), 919 (w), 850 (m), 797 (m).)
cm-1. GC-MS (EI): m/z (%) = 211 (20), 163 (9), 135 (100), 77 (84), 59 (31).
Submitted to the European Journal of Organic Chemistry
4

(4R,5R)-2,2-Dimethyl-1,3-dioxolane-4,5-dicarboxylic acid (24)
2.0 g (8.5 mmol, 1 equiv) of compound 16 were dissolved in 30 ml of distilled water. The solution was cooled to 0 °C and
acidified with 1M HCl (pH ≤ 2). The reaction mixture was extracted three times with 50 ml of EtOAc, the combined organic
layers were dried over MgSO4 and the solvent was removed under reduced pressure. After drying under vacuum compound
24 (1.6 g, 8.4 mmol, 99%) was obtained as a white solid.
1
m.p. = 90 °C, H NMR (300 MHz, CDCl3): δ = 4.81 (s, 2H, H3), 1.43 (s, 6H, H1). 13C NMR (APT,
75 MHz, CDCl3): δ = 171.0 (C4), 113.7 (C2), 77.5 (C3), 26.5 (C1). IR (ATR): 3340 (br, m), 2989 (m),
2933 (m), 2553 (br, m), 2228 (m), 1730 (s), 1688 (s), 1375 (s), 1246 (s), 1206 (s), 1105 (s), 1046 (s),
953 (m), 853 (s), 812 (s) cm-1.
(2S,3S,5R,6R)-2,3-Bis(hydroxymethyl)-5,6-dimethyl-5,6-dimethoxy-1,4-dioxane (19)
Under an argon atmosphere 1.05 g (27.6 mmol, 4 equiv) of LiAlH4 were suspended in 15 ml of dry THF and cooled to 0 °C.
2.0 g (6.9 mmol, 1 equiv) of 18 were dissolved in 15 ml of dry THF and added dropwise to the suspension. The mixture was
heated under reflux for 2 h. After cooling to room temperature, the mixture was carefully quenched with 4 ml of water and
2 ml of 15% w/w NaOH. The resulting suspension was stirred for 2 h at room temperature, which changed the color from
gray to white. The solvent was removed under reduced pressure, the white solid was transferred to a Soxhlet extractor and
heated to reflux for 24 h with dry THF. The solvent of Soxhlet-extraction was dried over MgSO4 and removed under reduced
pressure. The resulting oil was purified by flash column chromatography (cyclohexane/EtOAc, 1:5) to give the chiral diol 19
(1.60 g, 6.76 mmol, 98%) as a colorless oil.
1
Rf = 0.2 (cyclohexane:EtOAc / 1:5), m.p. = 117 °C, H NMR (300 MHz, CDCl3): δ = 3.76 (d, J =
31.7 Hz, 4H, H4), 3.68 (t, J = 15.9 Hz, 2H, H3), 3.26 (s, 6H, H5), 2.59 (s, 2H, OH), 1.31 (s, 6H, H1).
13C NMR (APT, 75 MHz, CDCl3): δ = 98.8 (C2), 69.3 (C3), 62.2 (C4), 47.9 (C5), 17.5 (C1). IR
(ATR): 3394 (br, OH), 2953 (m), 2927 (m), 1643 (w), 1450 (m), 1423 (m), 1379 (s), 1226 (m), 1116
(vs), 1039 (vs), 959 (vs), 855 (vs) cm-1. GC-MS (EI): m/z (%) = 173 (15), 112 (11), 101 (12), 87 (11),
75 (78), 70 (100). HRMS (ESI): calcd. for C10H20O6Na [M+Na]+ 259.1152; found 259.1151.
(2R, 3R, 5R, 6R)-Disodium-5,6-dimethoxy-5,6-dimethyl-1,4-dioxane-2,3-dicarboxylate (20)
In a 100 ml two-necked flask 2.45 g (8.4 mmol, 1 equiv) of dioxane 18 were dissolved in 30 ml of EtOH and heated to 70 °C.
0.70 g (17.6 mmol, 2.1 equiv) of NaOH were dissolved in 4 ml of water, diluted with 20 ml of EtOH and the resulting
solution was added dropwise to the reaction mixture. The mixture was heated under reflux for 15 min and the solvent was
removed under reduced pressure. The white solid was washed three times with 50 ml of cold EtOH and dried under vacuum
to give compound 20 (2.25 g, 7.3 mmol, 87%) as a white solid.
Submitted to the European Journal of Organic Chemistry
5

1
m.p. = 298-315 °C (decomposition), H NMR (300 MHz, CDCl3): δ = 4.15 (s, 2H, H3), 3.30 (s,
6H, H5), 1.33 (s, 6H, H1). 13C NMR (APT, 75 MHz, CDCl3): δ = 174.8 (C4), 99.0 (C2), 72.7
(C3), 47.9 (C5), 16.8 (C1). (ATR): 2989 (w), 2951 (w), 2358 (w), 1599 (s), 1411 (m), 1373 (m),
1211 (w), 1118 (s), 1028 (s), 970 (w), 914 (m), 889 (m), 850 (m), 800 (m), 779 (m), 759 (m), 688
(m), 669 (m) cm-1. HRMS (ESI): calcd. for C10H14O8Na [M-Na]- 285.0592; found 285.0591.
(2R, 3R, 5R, 6R)-5,6-Dimethoxy-5,6-dimethyl-1,4-dioxane-2,3-dicarboxyl dichloride (21)
Under an argon atmosphere 2.0 g (6.5 mmol, 1 equiv) of compound 20 were suspended in 20 ml of dry benzene and the
resulting suspension was cooled to 0 °C. 3.4 ml (39 mmol, 6 equiv) of oxalyl chloride were slowly added to the suspension,
the resulting mixture was heated under reflux for 1 h and then stirred over night at room temperature. The solvent was
removed under reduced pressure and the resulting solid was suspended in 100 ml CH2Cl2. The suspension was stirred at room
temperature for 1 h, before the mixture was filtered through a glass frit and washed with CH2Cl2. The solvent was removed
under reduced pressure and the resulting black oil was dried under vacuum, to give 1.5 g (4.9 mmol, 76%) of 21.
1H NMR (300 MHz, CDCl3): δ = 3.78 (s, 2H, H3), 3.32 (s, 6H, H5), 1.36 (s, 6H, H1). IR (ATR): 3486
(br, w), 2952 (m), 2853 (w), 1744 (s), 1636 (w), 1438 (m), 1378 (m), 1280 (m), 1211 (s), 1176 (m),
1100 (s), 1105 (s), 1112 (s), 1033 (s), 887 (m), 853 (m), 806 (m), 740 (m), 700 (w) cm-1. HRMS (ESI):
calcd. for C10H14Cl2O6Na [M+Na]+ 323.0059; found 323.0060 (2x35Cl).
3. Synthesis of borane-protected phosphanyl phenols
Ph
OH
OH
OH
OH
OH
OH
OH
OH
PPh2
BH3
PPh2
BH3
PPh2
BH3
PPh2
BH3
PPh2
BH3
PEt2
BH3
PPh2
BH3
P(i-Pr)2
BH3
4a
4b
4c
4d
4e
4f
4g
4h
A) A round-bottom flask was equipped with a Soxhlet extractor and a reflux condenser with a drying tube. The Soxhlet
extractor was equipped with an extraction thimble, which was filled with N-Bromosuccinimide (1.1 equiv). The flask was
charged with substituted phenol 3 (1.0 equiv), which was dissolved in CH2Cl2 before diisopropylamine (0.1 equiv) was added.
The solution was then heated to reflux for 16 h. After cooling to room temperature the mixture was treated with 2M H2SO4,
transferred into a separatory funnel, and the organic layer was collected. The aqueous layer was extracted with MTBE. The
combined organic layers were washed with brine, dried over MgSO4 and filtered. The solvent was removed under reduced
pressure and the crude product was purified by flash column chromatography (cyclohexane/EtOAc) to afford bromophenol 38
as light yellow oil.
B) Under an argon atmosphere bromophenol 38 (1.0 equiv) and DABCO (1.2 equiv) were dissolved in dry CH2Cl2 and stirred
15 min at room temperature. The resulting solution was cooled to 0 °C, and ClPPh2 (1.2 equiv) was added dropwise via
syringe over a period of 30 min. The resulting white suspension was stirred for 10 min at this temperature, then allowed to
warm to room temperature and stirred for another 2 h. The reaction mixture was then cooled to 0 °C again and a solution of
BH3-THF (1M, 2.0 equiv) was added via syringe. The suspension was stirred for 10 min at 0 °C, then allowed to warm to
room temperature and stirred for another 1 h. The reaction mixture was quenched with deionized water, the organic layer was
separated and the aqueous layer was extracted with MTBE. The combined organic layers were washed with brine, dried over
MgSO4. The solvent was removed under reduced pressure and the crude product was purified by flash column
chromatography (cyclohexane/EtOAc) to afford borane-protected phosphinite 39 as a white solid.
Submitted to the European Journal of Organic Chemistry
6

C) Under an argon atmosphere borane-protected phosphinite 39 (1.0 equiv) was dissolved in dry THF. The solution was
cooled to 0 °C before n-BuLi (1.5 equiv) was added via syringe over 30 min. The resulting yellow to red solution was stirred
for 2 h at 0 °C and then quenched with deionized water. The mixture was transferred into a separatory funnel and the organic
layer was collected. The aqueous layer was extracted with MTBE. The combined organic layers were washed with saturated
aqueous NH4Cl-solution, dried over MgSO4 and filtered through a glass frit. Removal of solvent under reduced pressure
afforded the crude product 4 as colorless oil, which was crystallized from EtOAc at 0 °C over 2 days. The mother liquor was
purified by flash column chromatography, eluting with cyclohexane.
2-Boranatodiphenylphosphanyl-6-methylphenol (4a)
Rf = 0.3 (cyclohexane/EtOAc, 50:1), 1H NMR (300 MHz, CDCl3): δ = 7.63 (s, 1H, OH), 7.55-7.40 (m, 10H, HAr), 7.27 (d, J =
7.2 Hz, 1H, HAr), 6.81-6.68 (m, 2H, HAr), 2.25 (s, 3H, CH3). 13C NMR (APT, 75 MHz, CDCl3): δ = 158.7 (d, J = 9.5 Hz, Cq),
135.0 (d, J = 2.1 Hz, CHAr), 133.0 (d, J = 9.9 Hz, CHAr), 131.9 (d, J = 3.1 Hz, CHAr), 131.5 (d, J = 2.5 Hz, CHAr), 128.9 (d,
J = 10.7 Hz, CHAr), 128.2 (d, J = 61.8 Hz, Cq), 127.5 (d, J = 6.2 Hz, Cq), 120.2 (d, J = 8.4 Hz, CHAr), 110.9 (d, J = 58.7 Hz,
Cq), 16.3 (CH3). 31P NMR {1H} (121 MHz, CDCl3): δ = 12.47 (d, J = 66.9 Hz, PR3). IR (ATR): 3359 (s), 3054 (w), 2953 (w),
2924 (w), 2856 (w), 2374 (s), 1585 (m), 1481 (m), 1456 (s), 1434 (s), 1422 (s), 1378 (m), 1343 (m), 1222 (s), 1180 (s), 1149
(m), 1102 (s), 1063 (s), 1027 (m), 998 (m), 863 (m), 827 (m), 739 (s), 690 (s), 647 (m) cm-1. GC-MS (EI): m/z (%) = 292 (100,
[M-BH3]+), 213 (55), 199 (28), 183 (34), 165 (17), 152 (14), 107 (20), 77 (17), 51 (18).
2-Boranatodiphenylphosphanyl-phenol (4b)
Rf = 0.2 (cyclohexane/EtOAc, 10:1), 1H NMR (300 MHz, CDCl3): δ = 7.57-7.40 (m, 12H, HAr, OH), 7.02-6.87 (m, 3H, HAr).
13C NMR (APT, 75 MHz, CDCl3): δ = 160.5 (d, J = 9.0 Hz, Cq), 134.4 (d, J = 3.3 Hz, CHAr), 134.0 (d, J = 1.9 Hz, CHAr),
133.0 (d, J = 10.0 Hz, CHAr), 131.5 (d, J = 2.5 Hz, CHAr), 128.9 (d, J = 10.6 Hz, CHAr), 128.0 (d, J = 61.7 Hz, Cq), 120.6 (d,
J = 7.9 Hz, CHAr), 118.4 (d, J = 6.1 Hz, CHAr), 111.7 (d, J = 58.6 Hz, Cq). 31P NMR {1H} (121 MHz, CDCl3): δ = 12.70 (d,
J = 66.3 Hz, PR3). IR (ATR): 3373 (m), 3053 (w), 2953 (w), 2380 (m), 1585 (m), 1580 (m), 1433 (s), 1330 (m), 1283 (m),
1213 (m), 1103 (m), 1056 (m), 830 (m), 753 (s), 740 (s), 690 (s) cm-1. GC-MS (EI): m/z (%) = 278 (100, [M-BH3]+), 199 (71),
183 (47), 170 (10), 152 (14), 107 (13), 77 (14), 51 (9).
2-Boranatodiphenylphosphanyl-6-ethylphenol (4c)
Rf = 0.5 (cyclohexane/EtOAc, 20:1), 1H NMR (300 MHz, CDCl3): δ = 7.63 (s, 1H, OH), 7.56-7.42 (m, 10H, HAr), 7.31 (d, J =
7.3 Hz, 1H, HAr), 6.83 (t, J = 8.1 Hz, 1H, HAr), 6.73 (m, 1H, HAr), 2.68 (q, J = 7.5 Hz, 2H, CH2), 1.22 (t, J = 7.5 Hz, 3H, CH3).
13C NMR (APT, 75 MHz, CDCl3): δ = 158.4 (d, J = 9.5 Hz, Cq), 133.4 (d, J = 5.8 Hz, Cq), 133.3 (d, J = 2.1 Hz, CHAr), 133.0
(d, J = 9.9 Hz, CHAr), 131.9 (d, J = 3.1 Hz, CHAr), 131.5 (d, J = 2.5 Hz, CHAr), 128.9 (d, J = 10.6 Hz, CHAr), 128.2 (d, J =
61.9 Hz, Cq), 120.3 (d, J = 8.4 Hz, CHAr), 111.0 (d, J = 58.6 Hz, Cq), 23.2 (d, J = 1.7 Hz, CH2), 13.7 (CH3). 31P NMR {1H}
(121 MHz, CDCl3): δ = 12.48 (d, J = 68.2 Hz, PR3). IR (ATR): 3359 (s), 3053 (w), 2963 (m), 2920 (w), 2860 (w), 2375 (s),
1583 (m), 1481 (m), 1435 (s), 1340 (m), 1221 (s), 1178 (m), 1149 (m), 1103 (s), 1063 (s), 1027 (m), 998 (m), 830 (m), 739 (s),
690 (s) cm-1. GC-MS (EI): m/z (%) = 306 (100, [M-BH3]+), 291 (12), 227 (23), 199 (30), 183 (46), 152 (15), 107 (21), 78 (38),
51 (26).
2-Boranatodiphenylphosphanyl-6-phenylphenol (4d)
Rf = 0.3 (cyclohexane/EtOAc, 50:1), 1H NMR (300 MHz, CDCl3): δ = 7.65-7.59 (m, 4H, HAr), 7.55-7.33 (m, 12H, HAr), 7.15
(s, 1H, OH), 7.13-7.07 (m, 1H, HAr), 7.00 (dt, J = 7.6 Hz, 1.6 Hz, 1H, HAr). 13C NMR (APT, 75 MHz, CDCl3): δ = 156.5 (d,
J = 6.7 Hz, Cq), 136.8 (Cq), 134.8 (CHAr), 134.2 (d, J = 5.5 Hz, CHAr), 133.0 (d, J = 9.9 Hz, CHAr), 131.4 (d, J = 1.8 Hz,
CHAr), 130.5 (d, J = 6.0 Hz, Cq), 129.3 (CHAr), 128.8 (d, J = 10.6 Hz, CHAr), 128.5 (CHAr), 127.7 (CHAr), 127.4 (d, J =
65.3 Hz, Cq), 120.8 (d, J = 9.4 Hz, CHAr), 113.2 (d, J = 57.3 Hz, Cq).31P NMR {1H} (121 MHz, CDCl3): δ = 14.75 (d, J =
66.9 Hz, PR3). IR (ATR): 3333 (m), 3053 (w), 2380 (m), 1963 (w), 1820 (w), 1576 (w), 1480 (m), 1433 (s), 1340 (m), 1223
(s), 1183 (m), 1146 (m), 1096 (s), 1063 (s), 1020 (m), 996 (m), 906 (m), 830 (m), 796 (m), 736 (s), 696 (s) cm-1. GC-MS (EI):
m/z (%) = 354 (100, [M-BH3]+), 275 (46), 257 (10), 199 (10), 183 (31), 170 (18), 152 (15), 108 (20), 78 (35), 51 (23).
2-Boranatodiphenylphosphanyl-5,6-dimethylphenol (4e)
Rf = 0.4 (cyclohexane/EtOAc, 10:1), 1H NMR (300 MHz, CDCl3): δ = 7.56-7.42 (m, 11H, HAr, OH), 6.72-6.59 (m, 2H, HAr),
2.28 (s, 3H, CH3), 2.18 (s, 3H, CH3). 158.3 (d, J = 9.7 Hz, Cq), 143.2 (d, J = 2.1 Hz, Cq), 133.0 (d, J = 9.9 Hz, CHAr), 131.4
(d, J = 2.5 Hz, CHAr), 131.0 (d, J = 3.0 Hz, CHAr), 128.9 (d, J = 10.6 Hz, CHAr), 128.5 (d, J = 61.9 Hz, Cq), 125.9 (d, J = 6.4
Hz, Cq), 122.2 (d, J = 8.4 Hz, CHAr), 108.2 (d, J = 60.7 Hz, Cq), 20.4 (CH3), 11.8 (CH3). 31P NMR {1H} (121 MHz, CDCl3):
δ = 12.38 (d, J = 61.1 Hz, PR3). IR (ATR): 3366 (s), 3055 (w), 2919 (w), 2375 (s), 1599 (m), 1563 (m), 1483 (m), 1435 (s),
1417 (s), 1380 (w), 1325 (s), 1231 (s), 1196 (m), 1103 (s), 1083 (s), 1066 (s), 1027 (w), 998 (m), 742 (s), 691 (s), 645 (m)
cm-1. GC-MS (EI): m/z (%) = 306 (100, [M-BH3]+), 289 (5), 227 (36), 213 (38), 197 (8), 183 (32), 165 (17), 133 (5), 107 (17),
91 (10), 77 (22), 51 (17).
Submitted to the European Journal of Organic Chemistry
7

2-Boranatodiphenylphosphanyl-1-naphthol (4f)
Rf = 0.5 (cyclohexane/EtOAc, 50:1), 1H NMR (300 MHz, CDCl3): δ = 8.70 (d, J = 1.1 Hz, 1H, HAr), 8.39 (d, J = 8.1 Hz, 1H,
HAr), 7.75 (d, J = 7.6 Hz, 1H, HAr), 7.60-7.44 (m, 12H, HAr, OH), 7.31 (d, J = 8.6 Hz, 1H, HAr), 6.93 (t, J = 9.0 Hz, 1H, HAr).
13C NMR (APT, 75 MHz, CDCl3): δ = 159.1 (d, J = 10.4 Hz, Cq), 136.2 (d, J = 1.7 Hz, Cq), 132.9 (d, J = 10.0 Hz, CHAr),
131.5 (d, J = 2.5 Hz, CHAr), 128.9 (d, J = 10.6 Hz, CHAr), 128.4 (d, J = 2.3 Hz, CHAr), 128.2 (Cq), 127.3 (CHAr), 126.2 (d,
J = 1.0 Hz, CHAr), 125.4 (d, J = 7.7 Hz, Cq), 123.5 (d, J = 1.6 Hz, CHAr), 120.2 (d, J = 7.5 Hz, CHAr), 102.5 (d, J = 60.4 Hz,
Cq). 31P NMR {1H} (121 MHz, CDCl3): δ = 12.05 (d, J = 67.0 Hz, PR3). IR (ATR): 3328 (s), 3053 (m), 2928 (w), 2373 (s),
1959 (w), 1891 (w), 1813 (w), 1755 (w), 1623 (s), 1589 (m), 1563 (s), 1499 (s), 1434 (s), 1399 (s), 1267 (s), 1199 (m), 1158
(s), 1127 (s), 1063 (s), 1025 (s), 998 (s), 907 (s), 880 (s), 856 (s), 803 (s), 737 (s), 690 (s), 663 (s) cm-1. GC-MS (EI): m/z (%)
= 328 (76, [M-BH3]+), 249 (100), 220 (11), 202 (19), 183 (14), 144 (10), 115 (12), 78 (65), 51 (20).
2-Boranatodiethylphosphanyl-6-methylphenol (4g)
1
Rf = 0.3 (cyclohexane/EtOAc, 5:1), H NMR (300 MHz, CDCl3): δ = 7.63 (s, 1H, OH), 7.26 (d, J = 6.8 Hz, 1H, HAr), 7.18-
7.12 (m, 1H, HAr), 6.88 (td, J = 7.4, 0.9 Hz, 1H, HAr), 2.25 (s, 3H, Ar-CH3), 2.04-1.78 (m, 4H, 2xCH2), 1.08 (dt, J = 17.3, 7.6
Hz, 6H, 2xCH2CH3). IR (ATR): 3364 (s), 2970 (m), 2934 (m), 2877 (m), 2369 (ss, BH3), 1587 (m), 1455 (ss), 1426 (ss), 1379
(m), 1347 (m), 1319 (w), 1300 (w), 1267 (w), 1220 (ss), 1209 (s), 1182 (ss), 1151 (m), 1070 (m), 1047 (w), 1031 (w), 1018
(m), 998 (w), 828 (m), 770 (ss), 744 (ss), 719 (w) cm-1. GC-MS (EI): m/z (%) = 196 (100, [M-BH3]+), 168 (99), 139 (69), 108
(43), 91 (64), 65 (11), 47 (27).
2-Boranatodi(isopropyl)phosphanyl-6-methylphenol (4h)
Rf = 0.5 (cyclohexane/EtOAc, 20:1), 1H NMR (300 MHz, CDCl3): δ = 8.11 (s, 1H, OH), 7.26 (d, J = 6.9 Hz,1H, HAr), 7.11 (td,
J = 8.1, 1.0 Hz, 1H, HAr), 6.85 (t, J = 7.5 Hz, 1H, HAr), 2.43-2.31 (m, 2H, 2xCH), 2.24 (s, 3H, Ar-CH3), 1.21 (dd, J = 16.1, 7.0
Hz, 6H, CH(CH3)2), 1.08 (dd, J = 14.6, 7.0 Hz, 6H, CH(CH3)2). IR (ATR): 3345 (s), 2962 (s), 2931 (m), 2871 (m), 2374 (s),
1588 (m), 1457 (s), 1423 (s), 1385 (m), 1368 (w), 1348 (m), 1298 (w), 1250 (w), 1220 (s), 1182 (s), 1150 (m), 1086 (m),
1034 (m), 996 (w), 931 (w), 882 (m), 861 (w), 828 (m), 754 (m), 739 (m), 688 (m) cm-1. GC-MS (EI): m/z (%) = 224 (70,
[M-BH3]+), 182 (88), 140 (100), 108 (24), 91 (72), 65 (10).
4. Analytical data of borane-protected ether-bridged bisphosphine ligand precursors
Borane-protected (4S,5S)-4,5-Bis((2-(diphenylphosphanyl)-6-methylphenoxy)methyl)-2,2-dimethyl-1,3-dioxolane (22a)
1
Rf = 0.3 (cyclohexane/EtOAc, 5:1), H NMR (300 MHz, CDCl3): δ = 7.66-7.57 (m, 8H, HAr), 7.44-7.28 (m, 14H, HAr), 7.02
(td, J = 7.6 Hz, 1.9 Hz, 2H, HAr), 6.93-6.86 (m, 2H, HAr), 3.66-3.56 (m, 6H, 2xCH, 2xCH2), 2.32 (s, 6H, 2x(Ar-CH3)), 1.23 (s,
6H, C(CH3)2). IR (ATR): 3055 (m), 2983 (m), 2926 (m), 2893 (m), 2379 (s, BH3), 2242 (m), 1573 (m), 1481 (m), 1453 (s),
1435 (s), 1368 (s), 1254 (s), 1213 (s), 1185 (s), 1153 (s), 1101 (s), 1055 (s), 997 (s), 906 (s), 850 (s), 825 (s), 781 (s), 726 (s),
692 (s) cm-1.
Borane-protected (4S,5S)-4,5-Bis((2-(diphenylphosphanyl)-phenoxy)-methyl)-2,2-dimethyl-1,3-dioxolane (22b)
1
Rf = 0.4 (cyclohexane/EtOAc, 4:1), H NMR (300 MHz, CDCl3): δ = 7.64-7.56 (m, 8H, HAr), 7.51 (t, J = 7.8 Hz, 2H, HAr),
7.44-7.31 (m, 14H, HAr), 7.03 (t, J = 7.5 Hz, 2H, HAr), 6.95 (d, J = 4.0 Hz, 1H, HAr), 6.92 (d, J = 4.0 Hz, 1H, HAr), 3.72 (dd,
J = 10.2 Hz, 2.8 Hz, 2H, CH2), 3.65 (dd, J = 10.2 Hz, 3.8 Hz, 2H, CH2), 3.27 (m, 2H, 2xCH), 1.14 (s, 6H, C(CH3)2). IR
(ATR): 3056 (w), 2983 (m), 2931 (w), 2880 (w), 2377 (s, BH3), 2242 (w), 1729 (m), 1586 (s), 1573 (m), 1476 (s), 1435 (s),
1370 (m), 1281 (s), 1239 (s), 1165 (s), 1134 (s), 1102 (s), 1056 (s), 1026 (s), 998 (m), 908 (s), 857 (m), 830 (m), 796 (w), 726
(s), 694 (s) cm-1.
Borane-protected (4S,5S)-4,5-Bis((2-(diphenylphosphanyl)-6-ethylphenoxy)-methyl)-2,2-dimethyl-1,3-dioxolane (22c)
Rf = 0.2 (cyclohexane/EtOAc, 20:1), 1H NMR (300 MHz, CDCl3): δ = 7.65-7.58 (m, 6H, HAr), 7.44-7.29 (m, 13H, HAr), 7.08
(td, J = 7.6 Hz, 1.6 Hz, 2H, HAr), 6.88 (m, 2H, HAr), 3.17 (s, 2H, 2xCH), 3.00-2.89 (m, 4H, 2xOCH2), 2.71 (m, 4H,
2xCH2CH3), 1.26 (t, J = 7.0 Hz, 6H, 2xCH2CH3), 1.24 (s, 6H, C(CH3)2). IR (ATR): 3055 (w), 2964 (m), 2931 (m), 2873 (w),
2381 (m, BH3), 2243 (w), 1571 (w), 1481 (m), 1445 (m), 1433 (s), 1402 (m), 1378 (m), 1369 (m), 1254 (m), 1212 (s), 1181
(s), 1151 (s), 1101 (s), 1055 (s), 998 (s), 906 (s), 856 (m), 793 (m), 726 (s), 690 (s) cm-1.
Borane-protected (4S,5S)-4,5-Bis((3-(diphenylphosphanyl)-biphenyl-2-yloxy)-methyl)-2,2-dimethyl-1,3-dioxolane (22d)
1
Rf = 0.3 (cyclohexane/EtOAc, 5:1), H NMR (300 MHz, CDCl3): δ = 7.70-7.60 (m, 8H, HAr), 7.48-7.46 (m, 6H, HAr), 7.38-
7.28 (m, 19H, HAr), 7.23-7.15 (m, 3H, HAr), 2.90-2.84 (m, 2H, 2xCH), 2.68-2.57 (m, 4H, 2xCH2), 0.86 (s, 6H, C(CH3)2). IR
(ATR): 3056 (m), 2983 (m), 2930 (m), 2379 (s, BH3), 2242 (m), 1957 (w), 1892 (w), 1815 (w), 1729 (m), 1599 (m), 1578 (m),
Submitted to the European Journal of Organic Chemistry
8

1495 (m), 1481 (s), 1448 (s), 1435 (s), 1420 (s), 1397 (s), 1369 (s), 1310 (m), 1207 (s), 1166 (s), 1103 (s), 1056 (s), 1023 (s),
990 (s), 905 (s), 847 (s), 802 (s), 725 (s), 690 (s) cm-1.
Borane-protected (4S,5S)-4,5-Bis((2-(diphenylphosphanyl)-5,6-dimethyl-phenoxy)-methyl)-2,2-dimethyl-1,3-dioxolane
(22e)
Rf = 0.4 (cyclohexane/EtOAc, 5:1), 1H NMR (300 MHz, CDCl3): δ = 7.65-7.56 (m, 8H, HAr), 7.43-7.30 (m, 12H, HAr), 6.94-
6.92 (m, 2H, HAr), 6.80 (d, J = 12.0 Hz, 1H, HAr), 6.77 (d, J = 12.0 Hz, 1H, HAr), 3.70 (m, 2H, 2xCH), 3.58 (m, 4H, 2xCH2),
2.31 (s, 6H, 2x(Ar-CH3)), 2.20 (s, 6H, 2x(Ar-CH3)), 1.25 (s, 6H, C(CH3)2). IR (ATR): 3216 (br), 3056 (w), 2945 (w), 2381 (m,
BH3), 2242 (w), 1588 (m), 1559 (w), 1445 (m), 1435 (s), 1404 (m), 1379 (m), 1256 (m), 1216 (s), 1198 (m), 1147 (m), 1101
(s), 1085 (s), 1057 (s), 998 (s), 907 (s), 846 (w), 812 (w), 731 (s), 693 (s) cm-1.
Borane-protected (4S,5S)-4,5-Bis((2-(diphenylphosphanyl)-naphthyl-1-yloxy)-methyl)-2,2-dimethyl-1,3-dioxolane (22f)
Rf = 0.3 (cyclohexane/EtOAc, 10:1), 1H NMR (300 MHz, CDCl3): δ = 8.39 (d, J = 8.3 Hz, 2H, HAr), 7.87 (d, J = 8.0 Hz, 2H,
HAr), 7.70-7.48 (m, 16H, HAr), 7.42-7.32 (m, 6H, HAr), 7.28 (m, 4H, HAr), 7.10 (d, J = 8.7 Hz, 1H, HAr), 7.07 (d, J = 8.6 Hz,
1H, HAr), 3.90 (m, 4H, 2xCH2), 3.82 (m, 2H, 2xCH), 1.38 (s, 6H, C(CH3)2). IR (ATR): 3054 (m), 2976 (m), 2928 (m), 2382 (s,
BH3), 2238 (m), 1560 (s), 1497 (m), 1435 (s), 1349 (s), 1325 (s), 1198 (s), 1163 (s), 1055 (s), 986 (m), 908 (s), 847 (m), 813
(s), 733 (s), 692 (s), 647 (m) cm-1.
Borane-protected (4S,5S)-4,5-Bis(2-diethylphosphanyl)-6-methylphenoxy)-methyl)-2,2-dimethyl-1,3-dioxolane (22g)
Rf = 0.4 (cyclohexane/EtOAc, 5:1), 1H NMR (300 MHz, CDCl3): δ = 7.53 (dd, J = 11.5, 7.7 Hz, 2H, HAr), 7.35 (d, J = 7.4 Hz,
2H, HAr), 7.13 (td, J = 7.6, 1.6 Hz, 2H, HAr), 4.45-4.43 (m, 2H, 2xCH), 4.29 (d, J = 10.0 Hz, 2H, OCH2), 4.15-4.10 (m, 2H,
OCH2), 2.39 (s, 6H, 2x(Ar-CH3)), 2.25-2.07 (m, 4H, 2xCH2CH3), 2.04-1.91 (m, 4H, 2xCH2CH3), 1.53 (s, 6H, C(CH3)2), 1.14-
0.96 (m, 12H, 4xCH2CH3). IR (ATR): 3367 (br), 3064 (w), 2958 (s), 2929 (ss), 2876 (m), 2849 (m), 2370 (s, BH3), 2256 (w),
1723 (w), 1585 (w), 1576 (w), 1486 (m), 1453 (ss), 1419 (s), 1398 (s), 1254 (s), 1212 (ss), 1185 (ss), 1166 (s), 1144 (s), 1086
(s), 1069 (s), 1004 (s), 850 (s), 773 (ss), 758 (ss), 722 (s) cm-1.
Borane-protected (4S,5S)-4,5-Bis(2-di(iso-propyl)phosphanyl)-6-methylphenoxy)-methyl)-2,2-dimethyl-1,3-dioxolane
(22h)
1
Rf = 0.4 (cyclohexane/EtOAc, 5:1), H NMR (300 MHz, CDCl3): δ = 7.58-7.52 (m, 2H, HAr), 7.25 (d, J = 7.4 Hz, 2H, HAr),
7.02 (t, J = 7.5 Hz, 2H, HAr), 4.39-4.29 (m, 2H, 2xOCH), 4.25-3.94 (m, 4H, 2xCH2), 2.76-2.64 (m, 2H, 2xCH(CH3)2), 2.62-
2.51 (m, 2H, 2xCH(CH3)2), 2.32 (s, 6H, 2x(Ar-CH3)), 1.44 (s, 6H, C(CH3)2), 1.16 (td, J = 14.5, 6.9 Hz, 12H, 2xCH(CH3)2),
0.92 (dd, J = 15.0, 6.6 Hz, 12H, 2xCH(CH3)2). IR (ATR): 2961 (s), 2930 (s), 2870 (m), 2374 (ss, BH3), 2266 (w), 1575 (w),
1452 (ss), 1420 (s), 1380 (s), 1369 (s), 1253 (s), 1212 (ss), 1184 (s), 1166 (m), 1151 (m), 1086 (s), 1045 (s), 1002 (m), 930
(m), 913 (m), 881 (m), 847 (m), 782 (m), 757 (s), 732 (s) cm-1.
Borane-protected (2S,3S,5R,6R)-2,3-Bis((2-(diphenylphosphanyl)-naphthyl-1-yloxy)-methyl)- 5,6-dimethoxy-5,6-
dimethyl-1,4-dioxane (22j)
1
Rf = 0.3 (cyclohexane/EtOAc, 10:1), H NMR (300 MHz, CDCl3): δ = 8.41-8.38 (m, 2H, HAr), 7.90-7.87 (m, 2H, HAr), 7.62-
7.47 (m, 15H, HAr), 7.25-7.22 (m, 3H, HAr), 7.19-7.12 (m, 6H, HAr), 7.08-6.97 (m, 4H, HAr), 3.84-3.72 (m, 4H, 2xCH2), 3.44-
3.41 (m, 2H, 2xCH), 2.98 (s, 6H, 2xOCH3), 1.30 (s, 6H, 2xCH3). IR (ATR): 3054 (w), 2989 (w), 2945 (w), 2830 (w), 2380
(m, BH3), 2345 (w), 2242 (w), 1730 (w), 1620 (w), 1585 (w), 1561 (m), 1500 (w), 1435 (s), 1362 (s), 1326 (m), 1262 (w),
1200 (m), 1164 (m), 1122 (s), 1076 (s), 1054 (s), 1028 (s), 998 (m), 977 (s), 962 (s), 907 (s), 861 (m), 813 (s), 729 (s), 691 (s),
646 (s) cm-1.
5. Synthesis of carbonate substrates
E-Crotyl methyl carbonate (30)
Under an argon atmosphere 10 ml (0.12 mol, 1.0 equiv) of E-Crotyl alcohol (34) and 29 ml (0.36 mol, 3.0 equiv) of dry
pyridine were dissolved in 150 ml of dry CH2Cl2. The solution was cooled to 0 °C and 14 ml (0.18 mol, 1.5 equiv) of
methylchloroformate (35) were added dropwise. The resulting mixture was stirred for 4 h at room temperature, before 200 ml
of HCl-solution (10%) were added to the reaction solution and the layers separated. The aqueous layer was extracted three
Submitted to the European Journal of Organic Chemistry
9

times with 100 ml of EtOAc. The combined organic layers were washed with 250 ml of brine and dried over MgSO4. The
solvent was removed under reduced pressure and the crude product was purified by flash column chromatography
(cyclohexane/EtOAc, 20:1). The carbonate 30 (13 g, 0.1 mol, 83%) was obtained as a colorless oil.
1
Rf = 0.40 (cyclohexane/EtOAc, 20:1), H NMR (300 MHz, CDCl3): δ = 5.90-5.78 (m, 1H, H3),
5.66-5.57 (m, 1H, H2), 4.56 (d, J = 6.5 Hz, 2H, H4), 3.78 (s, 3H, H6), 1.73 (d, J = 6.3 Hz, 3H, H1).
13C NMR (APT, 75 MHz, CDCl3): δ = 155.6 (C5), 132.2 (C3), 124.5 (C2), 68.5 (C4), 54.6 (C6),
17.7 (C1). IR (ATR): 3025 (w), 2955 (m), 2919 (w), 2856 (w), 1741 (s), 1676 (m), 1586 (w), 1440
(s), 1376 (s), 1250 (s), 1145 (m), 1106 (m), 1080 (m), 1042 (m), 966 (s), 939 (s), 913 (s), 891 (s),
791 (s) cm-1. GC-MS (EI): m/z (%) = 130 (10, [M]+), 98 (8), 71 (100), 54 (90).
4-Methoxyphenyl chloroformate (36)
Under an argon atmosphere 7.6 ml (12.46 g, 63 mmol, 1.5 equiv) of diphosgene were dissolved in 90 ml of dry THF and the
solution was cooled to 0 °C. In a further Schlenk flask 5.22 g (42 mmol, 1 equiv) of 4-methoxyphenol 29 and 5.8 ml (4.25 g,
42 mmol, 1 equiv) of triethylamine were dissolved in 50 ml of dry THF and the resulting solution was added over 15 min to
the first reaction mixture. The solution was stirred for 90 min at room temperature before 0.1 g of activated charcoal was
added. The black suspension stirred for further 10 min at room temperature and then filtered through a pad of silica gel and
washed with EtOAc. The filtrate was concentrated under reduced pressure and the crude product was purified by flash column
chromatography (cyclohexane/EtOAc, 10:1) to give compound 36 (7.1 g, 38.0 mmol, 90%) as a light yellow oil.
Rf = 0.20 - 0.50 (cyclohexane/EtOAc, 10:1), 1H NMR (300 MHz, CDCl3): δ = 7.13 (d, J = 9.1 Hz,
2H, H3+H3'), 6.90 (d, J = 9.1 Hz, 2H, H4+H4'), 3.80 (s, 3H, H1). 13C NMR (APT, 75 MHz,
CDCl3): δ = 158.1 (C2), 149.8 (C6), 145.2 (C5), 121.2 (C3+C3'), 114.6 (C4+C4'), 55.5 (C1). IR
(ATR): 3005 (w), 2958 (w), 2909 (w), 2836 (w), 1853 (w), 1771 (s), 1606 (m), 1596 (m), 1498 (s),
1464 (m), 1440 (m), 1355 (w), 1297 (m), 1249 (s), 1174 (s), 1157 (s), 1094 (s), 1029 (s), 1007 (s),
928 (m), 862 (s), 810 (s), 736 (m), 701 (s), 677 (s) cm-1. GC-MS (EI): m/z (%) = 186 (27, [M]+), 123 (100), 107 (21), 95 (31),
77 (11), 63 (30).
(E)-But-2-en-1-yl-(4-methoxyphenyl) carbonate (31)
Under an argon atmosphere 5.6 g (30 mmol, 1.0 equiv) of 36 and 3.8 ml (3.25 g, 45 mmol, 1.5 equiv) of E-crotyl alcohol
were dissolved in 60 ml dry CH2Cl2 and the resulting solution was stirred at room temperature for 20 min. 0.37 g (3 mmol,
0.1 equiv) of DMAP was added to the solution and the reaction mixture was cooled to 0 °C. Then, 3.15 ml (39 mmol,
1.3 equiv) of dry pyridine were added dropwise to the solution and the mixture was stirred at room temperature for 3 h.
100 ml of a 1 M HCl-solution were added to the reaction mixture and the layers separated. The aqueous layer was extracted
twice with 100 ml MTBE and the combined organic layers were dried over MgSO4. The solvent was removed under reduced
pressure and the crude product was purified by flash column chromatography (cyclohexane/EtOAc, 20:1). The carbonate 31
(6.1 g, 27.5 mmol, 92%) was obtained as a colorless oil.
Rf = 0.30 (cyclohexane/EtOAc, 20:1), 1H NMR (300 MHz, CDCl3): δ = 7.09 (d,
3
O
J = 9.0 Hz, 2H, H3+H3'), 6.87 (d, J = 9.0 Hz, 2H, H4+H4'), 5.95-5.84 (m, 1H, H8),
5.72-5.62 (m, 1H, H9), 4.65 (d, J = 6.6 Hz, 2H, H7), 3.78 (s, 3H, H1), 1.75 (d,
J = 6.2 Hz, 3H, H10). 13C NMR (APT, 75 MHz, CDCl3): δ = 157.3 (C2), 153.9 (C6),
144.7 (C5), 132.9 (C8), 124.1 (C9), 121.8 (C3+C3'), 114.3 (C4+C4'), 69.2 (C7), 55.5
1
2
4
5
O
8
3'
10
6
9
7
O
O
4'
(C1), 17.8 (C10). IR (ATR): 3003 (w), 2950 (w), 2915 (w), 2835 (w), 1752 (s), 1675 (w), 1609 (w), 1596 (w), 1504 (s), 1462
(m), 1441 (m), 1376 (m), 1296 (m), 1233 (s), 1195 (s), 1160 (s), 1101 (m), 1086 (m), 1028 (s), 1007 (m), 965 (s), 933 (m),
914 (m), 896 (m), 826 (s), 778 (s), 751 (s), 691 (w) cm-1. GC-MS (EI): m/z (%) =222 (2, [M]+), 124 (100), 109 (69), 95 (8), 81
(34), 55 (85).
Submitted to the European Journal of Organic Chemistry
10

6. 1H and 13C NMR spectra of carbonate substrates
1H and 13C NMR spectra of 30 in CDCl3
Submitted to the European Journal of Organic Chemistry
11

1H and 13C NMR spectra of 31 in CDCl3
Submitted to the European Journal of Organic Chemistry
12

7. 1H and 13C NMR spectra of 1-(but-3-en-2-yloxy)-4-methoxybenzene (32) in CDCl3
Submitted to the European Journal of Organic Chemistry
13

8. 1H and 13C NMR spectra of ether-, ester-, amide- and amine-bridged bisphosphine ligands
1H and 13C NMR spectra of 23a in CDCl3
Submitted to the European Journal of Organic Chemistry
14

1H and 13C NMR spectra of 23b in CDCl3
Submitted to the European Journal of Organic Chemistry
15

1H and 13C NMR spectra of 23c in CDCl3
Submitted to the European Journal of Organic Chemistry
16

1H and 13C NMR spectra of 23d in CDCl3
Submitted to the European Journal of Organic Chemistry
17

1H and 13C NMR spectra of 23e in CDCl3
O
O
O
O
PPh2
Ph2P
Submitted to the European Journal of Organic Chemistry
18

1H and 13C NMR spectra of 23f in CDCl3
Submitted to the European Journal of Organic Chemistry
19

1H and 13C NMR spectra of 23g in CDCl3
8.0
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0
f1 (ppm)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
180
170
160
150
140
130
120
110
100
90
f1 (ppm)
80
70
60
50
40
30
20
10
0
Submitted to the European Journal of Organic Chemistry
20

1H and 13C NMR spectra of 23h in CDCl3
8.0
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0
f1 (ppm)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
180
170
160
150
140
130
120
110
100
90
f1 (ppm)
80
70
60
50
40
30
20
10
0
Submitted to the European Journal of Organic Chemistry
21

1H and 13C NMR spectra of 23i in CDCl3
Submitted to the European Journal of Organic Chemistry
22

1H and 13C NMR spectra of 23j in CDCl3
Submitted to the European Journal of Organic Chemistry
23

1H and 13C NMR spectra of 25a in CDCl3
Submitted to the European Journal of Organic Chemistry
24

1H and 13C NMR spectra of 25b in CDCl3
Submitted to the European Journal of Organic Chemistry
25

1H and 13C NMR spectra of 25c in CDCl3
Submitted to the European Journal of Organic Chemistry
26

1H and 13C NMR spectra of 25d in CDCl3
Submitted to the European Journal of Organic Chemistry
27

1H and 13C NMR spectra of 27a in CDCl3
Submitted to the European Journal of Organic Chemistry
28

1H and 13C NMR spectra of 27b in CDCl3
Submitted to the European Journal of Organic Chemistry
29