Page 5 of 7
Journal of the American Chemical Society
Number JP17H06449 (Hybrid Catalysis), Kanazawa University
imine were tolerated (8ad, 8ae, 8ca, 8da, 8fa, 8ia, 8la and
SAKIGAKE project 2018.
1
2
3
8oa). Notably, this protocol enabled the reductive coupling of
aldehyde and ketimine to construct a complex b-amino alcohol
scaffold (8af).
REFERENCES
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(2) For selected papers on the intermolecular cross-pinacol coupling reaction,
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4
5
6
7
8
9
Table 4. Reductive coupling of aldehydes and iminesa
CuCl (10 mol %)
SIMes•HCl (10 mol %)
R4
OH
O
N
PhMe2SiBpin
NHR4
+
R1
R1
R2 R3
imine
7
H
NaOtBu
toluene, 80 oC, 12 h
then TBAF
R
2 R3
aldehyde
8
1
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
OH
H
N
OH
OH
OMe
OH
H
N
H
N
H
N
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph Ph
8ad, 56%
8aa, 74%
8ab, 56%
8ac, 51%
F
OH
H
OH
Me OH
OH
H
N
H
N
H
N
N
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
tBu
OMe
8fa, 62%
8ae, 95%
8ca, 86%
8da, 70%
OMe
OH
H
N
OH
OH
OH
H
N
H
N
H
N
Ph
Ph
S
Ph
Ph
Ph
Me
Ph
Ph
8oa, 70%
Ph
8la, 64%
CF3O
Cl
8ia, 79%
8af, 60%
a
Reactions were carried out with
1
(0.3 mmol), 7 (0.2 mmol),
a,a-Disubstituted
a-(Diphenylphosphinoyl)acetaldehydes
PhMe2SiBpin (0.3 mmol), CuCl (10 mol %), SIMes·HCl (10 mol %),
NaOtBu (0.22 mmol) in toluene (1.0 mL) at 80 °C for 12 h. Diastereomer-
ic ratio (1.2:1~3.5:1).
[Ph2P(O)CR1R2CHO] and Saturated Aldehyde. J. Org. Chem. 1990, 55,
5924. (d) Annunziata, R.; Cinquini, M.; Cozzi, F.; Giaroni, P. Vanadi-
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Cross Coupling. Tetrahedron: Asymmetry 1990, 1, 355. (e) Konradi, A.
W.; Kemp, S. J.; Pedersen, S. F. Pinacol Cross Coupling of 2-[N-
(Alkoxycarbonyl)amino] Aldehydes and Aliphatic Aldehydes by
3. Conclusion.
[V2Cl3(THF)6]2[Zn2Cl6].
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syn,syn-3-[N-
(Alkoxycarbonyl)amino] 1,2-Diols. J. Am. Chem. Soc. 1994, 116, 1316.
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U.; Jung, M.; Lindenmaier, M.; Vogel, T. Influence of Chelating Silyl
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M.; Vogel, T. Chromium-Catalyzed Pinacol-Type Cross-Coupling: Stud-
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Shen, Z.-L.; Loh, T.-P. Zn/InCl3-Mediated Pinacol Cross-Coupling Reac-
tions of Aldehydes with a,b-Unsaturated Ketones in Aqueous Media.
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nium. Synthesis 2009, 277. (l) Scheffler, U.; Stößer, R.; Mahrwald, R.
Retropinacol/Cross-Pinacol Coupling Reactions – A Catalytic Access to
1,2-Unsymmetrical Diols. Adv. Synth. Catal. 2012, 354, 2648. (m)
Miyasaka, A.; Amaya, T.; Hirao, T. Synthesis of Heterodinuclear Hemi-
salen Complexes on a Hexaarylbenzene Scaffold and their Application
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Am. Chem. Soc. 1958, 80, 1886. (b) Brook, A. G. Molecular Rearrange-
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We have developed the copper-catalyzed reductive coupling
of two different carbonyls. The reaction between aromatic
aldehydes and arylketones with a silylboronate proceeded
under mild conditions to produce cross-coupled 1,2-diol deriv-
atives. A reaction pathway is proposed that involves the cata-
lytic generation of a-silyloxybenzylcopper(I) from an aro-
matic aldehyde and its subsequent coupling with an arylketone.
Asymmetric reductive coupling was also achieved with a new
chiral NHC ligand on copper. This copper-catalyzed method
provides a new and efficient umpolung strategy for the organic
synthesis of 1,2-diol compounds. Efforts to expand the utility
of this reaction are ongoing in our laboratory
Supporting Information. Experimental details and characteriza-
tion data for all new compounds (PDF). This material is available
AUTHOR INFORMATION
Corresponding Author
(4) (a) Takeda, M.; Yabushita, K.; Yasuda, S.; Ohmiya, H. Synergistic Palla-
dium/Copper-Catalyzed Csp3–Csp2 Cross-Couplings Using Aldehydes as
Latent a-Alkoxyalkyl Anion Equivalents. Chem. Commun. 2018, 54,
6776. (b) Yabushita, K.; Yuasa, A.; Nagao, K.; Ohmiya, H. Asymmetric
Catalysis Using Aromatic Aldehydes as Chiral a-Alkoxyalkyl Anions. J.
Am. Chem. Soc. 2018, DOI: 10.1021/jacs.8b11495.
(5) For cross-pinacol-type couplings between isatins and aldehydes via a polar
two-electron reaction mechanism, see: (a) Horwitz, M. A.; Tanaka, N.;
Yokosaka, T.; Uraguchi, D.; Johnson, J. S.; Ooi, T. Enantioselective Re-
ductive Multicomponent Coupling Reactions between Isatins and Alde-
ORCID
Hirohisa Ohmiya: 0000-0002-1374-1137
Kazunori Nagao: 0000-0003-3141-5279
ACKNOWLEDGMENT
This work was supported by JSPS KAKENHI Grant Number
JP18H01971 to Scientific Research (B), JSPS KAKENHI Grant
ACS Paragon Plus Environment