10.1002/adsc.201701603
Advanced Synthesis & Catalysis
CH-N), 6.10 (m, 1H, CH=), 6.7-7.9 (m, 17H, CH=), 8.20
(s, 1H, CH=). Minor isomer: 31P NMR (162 MHz, CD2Cl2)
δ 104.6 (b, 1P). 1H NMR (400 MHz, CD2Cl2), δ: 0.45 (s,
[Pd(I)(Ph)(L2a)] (30 mg, 0.031 mmol) in dry degassed
THF (4 ml) under Ar atmosphere at r.t.. Stirring was
continued for 1h, during which period a pale grey
precipitate was formed. The reaction mixture then filtered
i
18H, SiMe3), 0.91 (d, 3H, 3JH-H= 5.6 Hz, CH3, Pr), 0.93 (d,
i
i
3H, 3JH-H= 5.6 Hz, CH3, Pr), 2.61 (m, 1H, CH, Pr), 4.24 (m, over celite, and all volatiles were removed under reduced
1H, CH2), 4.31 (m, 2H, CH2-O), 4.40 (m, 1H, CH2), 4.73
(m, 1H, CH-N), 5.94 (m, 1H, CH=), 6.7-7.9 (m, 17H,
CH=), 8.25 (s, 1H, CH=).
pressure to yield the final product as a pale brown solid (55
1
mg, 90 %). 31P NMR (162 MHz, CD2Cl2), δ: 96.99. H
3
NMR (401 MHz, CD2Cl2), δ: 7.59 (d, 1H, JH-H = 2.3 Hz,
3
CH=), 7.47 (d, 1H, JH-H = 2.1 Hz, CH=), 7.34 – 7.27 (m,
3H, CH=), 7.09 (t, 1H, 3JH-H = 7.5 Hz, CH=), 7.01 (dd, 1H,
3JH-H = 7.9, 1.3 Hz, CH=), 6.99 – 6.88 (m, 5H, CH=), 5.84
(Iodo)(phenyl)[(4S)-2-(2-(((11bS)-2,6-
bis(trimethylsilyl)dinaphtho[2,1-d:1',2'-
2
(d, 1H, 3JH-H = 8.1 Hz, CH=), 4.57 (d, 1H, JH-H = 14.6 Hz,
f][1,3,2]dioxaphosphepin-4-yl)oxy)benzyl)-4-isopropyl-
4,5-dihydrooxazole]palladium [Pd(I)(Ph)(L2c)] (18).
Yield: 36 mg (73%). MS HR-ESI [found 860.1961,
3
CH2), 4.48 (d, 1H, JH-H = 8.3 Hz, CH2˗O), 4.38 (m, 1H,
CH-N), 4.29 (m, 1H, CH2˗O), 3.71 (d, 1H, 2JH-H = 14.5 Hz,
CH2), 2.52 (m, 1H, CH, iPr), 1.60 (s, 9H, CH3, tBu), 1.54 (s,
+
C45H49NO4PPdSi2 requires 860.1967]. Major isomer: 31P
t
t
1
9H, CH3, Bu), 1.34 (s, 9H, CH3, Bu), 1.30 (s, 9H, CH3,
tBu), 1.07 (d, 3H, iPr, 3JH-H = 6.9 Hz), 1.03 (d, 3H, iPr, 3JH-H
= 6.7 Hz).13C NMR (101 MHz, CD2Cl2), δ: 169.2 (C=N),
151.7˗121.3 (aromatic carbons), 70.9 (CH˗O), 69.8 (CH-
NMR (162 MHz, CD2Cl2) δ 101.2. H NMR (400 MHz,
CD2Cl2), δ: 0.62 (s, 9H, SiMe3), 0.65 (s, 9H, SiMe3), 1.02
i
(d, 3H, 3JH-H= 5.8 Hz, CH3, Pr), 1.10 (d, 3H, 3JH-H= 5.6 Hz,
i
2
CH3, iPr), 2.74 (m, 1H, CH, Pr), 3.57 (d, 1H, JH-H= 11.0
t
2
N), 34.5 (CH2), 34.1 (C), 33.9 (C), 31.9 (CH3, Bu), 31.6
Hz, CH2), 4.27 (m, 1H, CH2-O), 4.41 (dd, 1H, JH-H= 8.4
t
t
t
i
3
2
(CH3, Bu), 31.4 (CH3, Bu), 31.0 (CH3, Bu), 30.0 (C, Pr),
Hz, JH-H= 7.2 Hz, CH2-O), 4.60 (d, 1H, JH-H= 11.0 Hz,
19.1 (CH3, Pr), 16.4 (CH3, Pr). 19F NMR (377 MHz,
CD2Cl2), δ: -78.01. MS HR-ESI [found 840.3372,
C47H61NO4PPd+ requires 840.3368].
i
i
3
CH2), 5.15 (m, 1H, CH-N), 5.84 (d, 1H, JH-H= 6.6 Hz,
CH=), 5.97 (m, 1H, CH=), 6.26 (m, 1H, CH=), 6.71 (m,
2H, CH=), 6.84 (m, 1H, CH=), 7.03 (m, 1H, CH=), 7.12
(m, 3H, CH=), 7.26 (m, 1H, CH=), 7.44 (m, 3H, CH=),
7.95 (m, 3H, CH=), 8.14 (s, 1H, CH=), 8.25 (s, 1H, CH=).
13C NMR (100 MHz, CD2Cl2), δ: 0.3 (CH3-Si), 0.46 (CH3-
General procedure for Pd-catalyzed enantioselective Heck
reactions with several triflates
i
i
i
Si), 16.1 (CH3, Pr), 19.6 (CH3, Pr), 30.6 (CH, Pr), 34.7
(CH2), 70.0 (CH2-O), 71.9 (CH-N), 113.7-138.2 (aromatic
A mixture of [Pd2(dba)3]·C6H6 (12 mg, 1.25 × 10-2 mmol)
and the corresponding chiral ligand (2.3 equiv) in dry
degassed solvent (3.0 mL) was stirred at room temperature
for 20 min. The corresponding olefin (2.0 mmol), triflate
(0.50 mmol) and N-diisopropylethylamine (1.0 mmol)
were added to the catalyst solution. The vial was sealed
and brought out and the solution was vigorously stirred at
the desired temperature. After the desired reaction time,
the reaction mixture was cooled to ambient temperature
and internal standard (undecane, 0.5 mmol) was added.
The mixture was diluted with additional diethyl ether and
after agitation, the mixture was filtered through a short
silica gel plug and analyzed by 1H-NMR or GC to
determine the conversion and regioselectivity. The crude
was subjected to flash chromatography (pentane/Et2O) to
give the purified product. Enantioselectivities were
determined using chiral HPLC or GC (see Supporting
Information for details).
carbons), 150.3 (d, C-O, JC-P= 11 Hz), 151.5 (d, C-O, JC-P
=
6.4 Hz), 151.6 (d, Cipso, JC-P= 18.6 Hz), 151.7 (d, C-O, JC-
P= 3.2 Hz), 166.5 (d, C=N, JC-P= 3.0 Hz). Minor isomer:
31P NMR (162 MHz, CD2Cl2) δ 110.8. 1H NMR (400 MHz,
CD2Cl2), δ: 0.63 (s, 9H, SiMe3), 0.66 (s, 9H, SiMe3), 1.02
(d, 3H, 3JH-H= 5.8 Hz, CH3, Pr), 1.09 (d, 3H, 3JH-H= 5.6 Hz,
i
CH3, iPr), 2.74 (m, 1H, CH, Pr), 3.59 (d, 1H, JH-H= 11.0
i
2
2
Hz, CH2), 4.27 (m, 1H, CH2-O), 4.46 (dd, 1H, JH-H= 8.2
3
2
Hz, JH-H= 7.2 Hz, CH2-O), 4.61 (d, 1H, JH-H= 11.4 Hz,
3
CH2), 4.95 (m, 1H, CH-N), 5.80 (d, 1H, JH-H= 6.6 Hz,
CH=), 6.13 (m, 1H, CH=), 6.71 (m, 2H, CH=), 6.84 (m,
1H, CH=), 6.90 (m, 1H, CH=), 7.03 (m, 1H, CH=), 7.12
(m, 3H, CH=), 7.26 (m, 1H, CH=), 7.44 (m, 3H, CH=),
7.95 (m, 3H, CH=), 8.11 (s, 1H, CH=), 8.26 (s, 1H, CH=).
13C NMR (100 MHz, CD2Cl2), δ: 0.2 (CH3-Si), 0.3 (CH3-
i
i
i
Si), 16.1 (CH3, Pr), 19.5 (CH3, Pr), 30.7 (CH, Pr), 34.7
(CH2), 69.4 (CH-N), 69.9 (CH2-O), 113.7-138.2 (aromatic
carbons), 150.4 (d, C-O, JC-P= 10 Hz), 151.4 (d, C-O, JC-P
6.4 Hz), 151.7 (d, C-O, JC-P= 3.0 Hz), 166.4 (d, C=N, JC-P
2.6 Hz).
=
=
Pd-catalyzed enantioselective Heck reactions of 2,3-
dihydrofuran with aryl halides
[(4S)-2-(2-(((11aS)-4,8-di-tert-butyl-1,2,10,11-
tetramethyldibenzo[d,f][1,3,2]dioxaphosphepin-6-
yl)oxy)benzyl)-4-isopropyl-4,5-
[Pd(dba)2]·C6H6 (8.5 mg, 0.013 mmol) and ligand (0.015
mmol) in degassed ethylene glycol (1.0 mL) were stirred at
room temperature for 20 min. Aryl halide (0.50 mmol), N-
diisopropylethylamine (255 μL, 1.5 mmol, 3 equiv), silver
triflate (192.7 mg, 0.75 mmol, 1.5 equiv) and 2,3-
dihydrofuran (75 μL, 1.0 mmol, 2 equiv) were added to the
catalyst solution. The vial was sealed and brought out and
the mixture was vigorously stirred in an oil bath at 80 oC,
for 24h. The reaction mixture was cooled to ambient
temperature and internal standard (undecane, 0.5 mmol)
was added. The mixture was diluted with additional diethyl
ether and after agitation, the mixture was filtered through a
dihydrooxazole](iodo)(phenyl)palladium
[Pd(I)(Ph)(L2e)] (19). Yield: 32 mg (71%). MS HR-ESI
[found 784.2739, C43H53NO4PPd+ requires 784.2742]. 31P
NMR (162 MHz, CD2Cl2) δ 91.3 (s). 1H NMR (400 MHz,
t
CD2Cl2), δ: 0.99 (s, 6H, CH3, iPr), 1.50 (s, 9H, CH3, Bu),
t
1.56 (s, 9H, CH3, Bu), 2.20 (s, 3H, CH3), 2.23 (s, 6H,
i
CH3) 2.30 (s, 3H, CH3), 2.73 (m, 1H, CH, Pr), 3.53 (d, 1H,
2JH-H= 14.0 Hz, CH2), 4.22 (m, 1H, CH2-O), 4.34 (m, 1H,
2
CH2-O), 4.56 (d, 1H, JH-H= 14.0 Hz, CH2), 5.05 (m, 1H,
3
CH-N), 5.84 (d, 1H, JH-H= 7.6 Hz, CH=), 6.51 (m, 2H,
CH=), 6.7-7.3 (m, 7H, CH=), 7.35 (s, 1H, CH=). 13C NMR
1
short silica gel plug and analyzed by H-NMR or GC to
i
i
(100 MHz, CD2Cl2), δ: 15.6 (CH3, Pr), 15.7 (CH3, Pr),
determine the conversion and regioselectivity. The crude
was subjected to flash chromatography (pentane/Et2O) to
give the purified product. Enantioselectivities were
determined using chiral HPLC or GC (see Supporting
Information for details).
i
19.1 (CH3), 19.7 (CH3), 20.0 (CH3), 30.8 (CH, Pr), 31.1
t
t
t
t
(CH3, Bu), 31.5 (CH3, Bu), 34.1 (C, Bu), 34.3 (C, Bu),
34.7 (CH2), 69.7 (CH2-O), 71.9 (CH-N), 121.0-143.7
(aromatic carbons), 145.3 (d, Cipso, JC-P= 16.4 Hz), 166.5
(C=N).
Synthesis of (iodo)[(S)-4-isopropyl-2-(2-((2,4,8,10-tetra-tert-
butyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy)benzyl)-4,5-
dihydrooxazole](trifluoromethanesulphonate)palladium
[Pd(Ph)(OTf)(L2a)] (26)
Acknowledgements
Financial support from the Spanish Ministry of Economy and
Competitiveness
(CTQ2016-74878-P,
and
CTQ2015-69136-R,
European Regional
CTQ2016-81293-REDC/AEI)
Silver triflate (16 mg, 0.062 mmol) was added to a
Development Fund (AEI/FEDER, UE), the Catalan Government
(2014SGR670, 2014SGR827 and 2017SGR1472), ICIQ (the
vigorously
stirred
solution
of
the
complex
11
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