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tered over a pad of Celite (rinsed with CH2Cl2) and the solvent was
evaporated. The residue was purified by FC (SiO2; pentane/EtOAc,
100:0 to 100:4) to afford 8 (20 mg, 67%).
Experimental Section
General experimental information
Wet conditions: Cu(OTf)2 (46 mg, 127 mmol, 0.1 equiv) and
A
All commercially available reagents were used as received. [John-
PhosAuCl] (A) was either purchased from Strem Chemicals or pre-
pared from Me2S·AuCl (Aldrich) and JohnPhos (Aldrich),[40] complex
B was prepared from Me2S·AuCl (Aldrich) and tris(2,4-di-tert-butyl-
phenyl)phosphite (Aldrich),[40] complex C was purchased from
Strem Chemicals, [(R)-DTBM-SEGPHOS-(AuCl)2] was prepared from
Me2S·AuCl (Aldrich) and (R)-DTBM-SEGPHOS (Aldrich),[41] Cu(OTf)2,
Al(OTf)3, GaCl3, InCl3 were purchased from Alfa Aesar, Zn(OTf)2,
In(OTf)3, Bi(OTf)3, Yb(OTf)3, Sc(OTf)3, TMSOTf, In(NTf2)3, AlCl3 were
purchased from Aldrich, Ga(OTf)3 was purchased from Acros. 1,2-
Dichloroethane (DCE), dichloromethane (CH2Cl2), and toluene were
distilled over calcium hydride. Tetrahydrofuran (THF) was distilled
over sodium. Methanol was used without purification. Wet DCE
was prepared by shaking DCE with water in a separatory funnel
followed by collection of the organic layer. Analytical thin-layer
chromatography (TLC) was performed on TLC silica gel plates
(0.25 mm) precoated with a fluorescent indicator. Flash chromatog-
raphy (FC) was performed on 40–63 mm silica gel. Visualization was
effected with ultraviolet light and/or p-anisaldehyde stain. NMR
spectra were recorded with AM250, AV300, AV360, or DRX400 MHz
Bruker spectrometers. 1H NMR chemical shifts were referenced to
the residual solvent signal; 13C NMR chemical shifts were refer-
enced to the deuterated solvent signal. Multiplicity was defined by
DEPT 135 analysis. Data are presented as follows: chemical shift d
(ppm), multiplicity (s=singlet, d=doublet, t=triplet, q=quadru-
plet, quint=quintuplet, m=multiplet, br=broad), coupling con-
stant J (Hz), integration. High-resolution mass spectra were ob-
tained by electrospray ionization with a TOF instrument (MicrO-
TOFq Bruker spectrometer). N-Allylbenzylamine[42] and N-benzyl-
but-3-en-1-amine[43] were prepared by following reported proce-
dures. Compounds 3,[44] 4,[45] 5,[46] 6,[46] 7,[40] 8,[40] 10,[47] 11,[48] 13,[20]
14a/14b,[20] 17a/17b,[21] 18,[49] 19,[49] 20,[24c] 22,[24c] methyl 2-
methyl-3-oxobutanoate,[50] methyl 1-oxo-1,2,3,4-tetrahydronaphtha-
lene-2-carboxylate,[51] and methyl 1-oxo-2,3-dihydro-1H-indene-2-
carboxylate,[52] were already described. Compounds 2g and 21
were only detected by analysis of the crude reaction mixture and not
isolated (in particular, 21 is unstable on silica). Characterization data
of the new products are provided in the Supporting Information.
(0.5 mgmLÀ1, 140 mL, 1.27 mmol, 0.1 mol%) were added to a solu-
tion of enyne 7 (400 mg, 1.27 mmol, 1 equiv) in wet DCE (13 mL).
The reaction was heated at 808C for 18 h, then the crude material
was filtered over a pad of Celite (rinsed with CH2Cl2) and the sol-
vent was evaporated. The residue was purified by FC (SiO2; pen-
tane/EtOAc, 100:0 to 100:4) to afford 9 (287 mg, 69%).
Alkoxycyclization of enyne 10 (Scheme 3): A solution of A
(0.5 mgmLÀ1, 58 mL, 0.055 mmol, 0.1 mol%) and Cu(OTf)2 (2 mg,
0.0055 mmol, 0.1 equiv) were added to a solution of enyne 10
(22 mg, 0.055 mmol, 1 equiv) in MeOH (1 mL). The resulting mix-
ture was stirred at 508C for 2.5 h and then filtered over a pad of
Celite (rinsed with CH2Cl2). The solvent was evaporated to afford
11 (15 mg, 66%).
Hydrations, hydroalkylation, hydroaminations, Meyer–
Schuster rearrangement
Hydration of alkynes (Table 3); general procedure: In air,
Cu(OTf)2 (y mol%), A or C (x mol%), THF and H2O (2:1 v/v, c=1m),
and alkyne (1.0 equiv) were charged in a 10 mL reaction tube
equipped with a stir bar and the tube was sealed. The reaction
was stirred at 1208C for 16 h, then the reaction mixture was
1
cooled to rt and the solution was analyzed by H NMR spectrosco-
py by using 4-methoxybenzaldehyde (1.0 equiv) as an internal
standard to determine conversion (by comparison with commercial
12).
Hydroalkylation of 13 (Scheme 4): In air, 13 (190 mg, 1.0 mmol,
1.0 equiv), Cu(OTf)2 (3.6 mg, 10 mmol, 1 mol%), A (0.5 mg, 1 mmol,
0.1 mol%), and CH2Cl2 (0.5 mL) were charged in a 10 mL reaction
tube equipped with a stir bar and the tube was sealed. The reac-
tion was stirred at rt for 24 h, then the reaction mixture was fil-
tered through a pad of Celite (rinsed with CH2Cl2) and evaporated
to afford the crude product. Purification by FC (SiO2; cyclohexane/
EtOAc 90:10 to 80:20) afforded a mixture of 14a/14b (1.5:1,
120 mg, 63%).
Hydroamination of alkyne 15b (Scheme 4); representative pro-
cedure: In air, Cu(OTf)2 (5.4 mg, 15 mmol, 1 mol%), A (0.8 mg,
2 mmol, 0.1 mol%), toluene (1.5 mL), 4-ethynylanisole (0.2 mL,
1.54 mmol, 1.0 equiv), and 2,6-diisopropylaniline (0.32 mL, 90%,
1.54 mmol, 1.0 equiv) were charged in a 10 mL reaction tube
equipped with a stir bar and the tube was sealed. The reaction
was stirred at 508C for 16 h, then the reaction mixture was cooled
Cycloisomerizations
Cycloisomerization of enyne 3 (Table 2, entry 2); representative
procedure:
A solution of A , 140 mL,
in DCE (0.5 mgmLÀ1
0.134 mmol, 0.1 mol%) and Cu(OTf)2 (4.8 mg, 13.4 mmol, 10 mol%)
were added to a solution of enyne 3 (30 mg, 0.134 mmol, 1 equiv)
in DCE (1 mL). After stirring for 3 h at rt, the mixture was filtered
on a pad of Celite (rinsed with CH2Cl2) and the solvent was re-
moved under reduced pressure to afford 4 (24 mg, 80%).
1
to rt and analyzed by H NMR spectroscopy, which showed 100%
conversion into 17b.
Meyer–Schuster rearrangement of 18 (Scheme 5): In air, 18
(376 mg, 2.15 mmol, 1.0 equiv), Cu(OTf)2 (36 mg, 100 mmol,
5 mol%), A (1.1 mg, 2 mmol, 0.1 mol%), MeOH (8.4 mL), and H2O
(1.6 mL) were charged in a 50 mL reaction tube equipped with
a stir bar and the tube was sealed. The reaction was stirred at
608C for 14 h, then the reaction mixture was concentrated and di-
luted with Et2O. The resulting solution was filtered through a pad
of Celite (rinsed with Et2O) and evaporated to afford the crude
product. Purification by FC (SiO2; cyclohexane/EtOAc, 95:5 to
90:10) afforded 19 (313 mg, 83%).
Cycloisomerization of arenyne 5 (Scheme 1): A solution of B
(0.5 mgmLÀ1, 174 mL, 0.103 mmol, 0.1 mol%) and Cu(OTf)2 (3.6 mg,
10 mmol, 10 mol%) were successively added to a solution of are-
nyne 5 (30 mg, 0.103 mmol, 1 equiv) in DCE (1 mL). After stirring
for 3 h at 808C, the mixture was filtered over a pad of Celite
(rinsed with CH2Cl2) and the solvent was removed under reduced
pressure to afford 6 (28.5 mg, 95%).
Cycloisomerization of arylenyne 7 (Scheme 2):
Dry conditions: Cu(OTf)2 (3.4 mg, 0.009 mmol, 10 mol%) and A
(0.5 mgmLÀ1, 100 mL, 0.09 mmol, 0.1 mol%) were added to a solu-
tion of enyne 7 (30 mg, 0.09 mmol, 1 equiv) in anhydrous dichloro-
ethane (1 mL). The reaction was heated to 808C for 18 h, then fil-
Hydroalkylations
Formation of type 2 products; general procedure: A solution of
1 (1.0 equiv), metal triflate (y mol%), and gold complex (x mol%)
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Chem. Eur. J. 2014, 20, 1 – 9
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