alkylation by asymmetric phase- transfer catalysis 张文全
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Alkylation by Asymmetric Phase-TransferCatalysis张文全
Keiji Maruoka, Professor
Keiji Maruoka was born in 1953 in Mie, Japan. He graduated from Kyoto University (1976) and received his Ph.D. (1980) from University of Hawaii(Thesis Director: Prof. H. Yamamoto). He became an assistant professor of Nagoya University (1980) and was promoted to a lecturer (1985) and an associate professor (1990) there. He moved to Hokkaido University as a full professor (1995-2001), and he currently is a professor of chemistry in Kyoto University since 2000. (2007/2008). He is a board member of Chem. Commun. and is a member of the international advisory editorial board of Org. Biomol. Chem. And Chem. Asian J. His current research interests include bidentate Lewisacids in organic synthesis and practical asymmetric synthesis with chiral C2-symmetric phase-transfer catalysts and chiral bifunctional organocatalysts..
• Design of Chiral Phase Transfer Catalysts for Practical Amino Acid Synthesis
• Design of Chiral Organocatalysts for Practical Asymmetric Synthesis Bronsted Acid Catalysts
• Development of Bidentate Lewis Acid Chemistry and Application to Selective Organic Synthesis
Alkylation
Michael Addition
Aldol and Related Reactions
Darzens Reaction
Neber Rearrangement
Horner¨CWadsworth¨CEmmons Reaction
Cyclopropanation
Epoxidation
Aziridination
Oxidation
Reduction
FluorinationSulfenylationCyanation
phase transfer catalysts
Alkylation
NPh
Ph
O
OR PTC cat. (xmol%)
PTC condition NPh
Ph
O
OR
HR'
R'X
N
HO
N
Cl
NPh
Ph
O
OtBu
Cl
Br cat 10mol%
50% Aq. NaOHCH2Cl2, 25oC
NPh
Ph
O
OtBu
Cl64 ee%95 yield%
Pioneering work
O’Donnell J. Am. Chem. Soc. 1989, 111, 2353.
cinchoninium
N
O
N
Br
cinchonidinium
Corey, E. J J. Am. Chem. Soc. 1997, 119, 12414.
NPh
Ph
O
OtBucat 10mol%
CsOH H2OCH2Cl2low temperture
NPh
Ph
O
OtBu
RX
R
99 >ee%
Lygo, B. Tetrahedron Lett. 1997, 38, 8595.
N
HO
N
R condition: cat 10mol%, RT, toluene, KOH/NaOH
almost all of the elaborated chiral phase-transfer catalysts reported so far have been restricted to cinchona alkaloid derivatives, which unfortunately constitutes a major difficulty in rationally designing and fine-tuning catalysts to attain sufficient reactivity and selectivity for various chemical transformationsunder phase-transfer catalyzed conditions
Design new PTC catalyst which contain C2-Symmetry
N
Br
R
R
NAr
ArBr
NPh
Ph
O
OtBucat 1mol%, 0oC
toluene-50% aq KOHNPh
Ph
O
OtBu
RXHR
J. Am. Chem. Soc. 1999, 121, 6519.
N
Br
N
Br
Ph
PhPh
Ph
SYNLETT 2003, 12, 1931
N
Br
R
R
R2
R2
Angew. Chem. Int. Ed. 2002, 41, 1551
N
Ar
Ar
Ar'
Ar'
Ar
Ar
Ar'
Ar'
T. A. 2003, 14, 1599
N
(C8F17H2CH2C)Me2Si
(C8F17H2CH2C)Me2Si
SiMe2(CH2CH2C8F17)
SiMe2(CH2CH2C8F17)
(F17C8CH2CH2)Me2Si SiMe2(CH2CH2C8F17)
SiMe2(CH2CH2C8F17)(F17C8CH2CH2)Me2Si
O.L. 2004, 6, 1429
NN
NNnBrBr
Tetrahedron: Asymmetry 2004, 15, 1243
OMe
OMe
MeO
MeO
MeO
MeO
OMe
OMe
N+Bu
BuBr-
T.L. 2005, 46, 8555
NPh
Ph
O
OR cat. (xmol%)
toluene-base NPh
Ph
O
OR
HR'
R'X
R= tBu, Me, Et, etc.
R'= Bn, Alk, etc.
N
O
OtBu
Cl
T. A. 2006, 17, 603
classical reaction：
NPh
Ph
O
OtBuBr
cat. (xmol%)
toluene-base0oC
NPh
Ph
O
OtBu
HN
p
p
Adv. Synth. Catal. 2002, No. 3+4, 344,
NPh
Ph
O
OtBu 1)R1X,2)R2X 0.5M citric acidH2N
O
OtBu
CsOH H2O/toluene-10oC-0oC
THFR1 R2
R1X= Br
R2X= PhCH2Br
J. Am. Chem. Soc. 2000, 122, 5228.
Anaerobic Conditions is needed Synlett 2001, 7, 1185
61yield%, 87ee%80yield%, 98ee%
NPh
Ph
O
OtBu R1
OBn
Br Chiral PTC (1mol%)
toluene-50% KOH aq 0oC, 1-2h
1M citric acid
THF, r.t. 10h
H2NO
OtBu
R1
OBn
10%Pd/C, H2
THF, r.t %h
H2NO
OtBu
R1
OH
Facile synthesis of L-Dopa tert-butyl ester
Tetrahedron Lett. 2000, 41, 8339.
For two chiral binaphthyl catalysts are difficult for their fruitful modificationsThey design more flexible one.
NPh
Ph
O
OtBucat 1mol%, 0oC
toluene-50% aq KOHNPh
Ph
O
OtBu
RXHR
>90 yield%>90 ee%
N
Br
R
R
R2
R2
flexible
Angew. Chem. Int. Ed. 2002, 41, 1551
N
(C8F17H2CH2C)Me2Si
(C8F17H2CH2C)Me2Si
SiMe2(CH2CH2C8F17)
SiMe2(CH2CH2C8F17)
(F17C8CH2CH2)Me2Si SiMe2(CH2CH2C8F17)
SiMe2(CH2CH2C8F17)(F17C8CH2CH2)Me2Si
NPh
Ph
O
OtBucat 1mol%, 0oC
toluene-50% aq KOHNPh
Ph
O
OtBu
RXHR
O.L. 2004, 6, 1429
NPh
Ph
O
OtBu chiral PTCachiral PTC
toluene-50% aq KOH 0oC
NPh
Ph
O
OtBu
RXHR
Angew. Chem. Int. Ed. 2005, 44, 625
3,4,5_F3C6H2
3,4,5_F3C6H2
N+Bu
Bu
NPh
Ph
O
OtBucat xmol%, 0oC
toluene-50% aq KOHNPh
Ph
O
OtBu
RXHR
x=0.1-0.01mol%
Angew. Chem. Int. Ed. 2005, 44, 1549
81-98 yield%97-99 ee%
OMe
OMe
MeO
MeO
MeO
MeO
OMe
OMe
N+Bu
BuBr-
>90 yield%>95 ee%
T.L. 2005, 46, 8555
Chem. Asian J. 2008, 3, 1702
O
CO2tBu
cat(1mol%)PhCH2Br(1.2eq)
toluene-base
O
CO2tBu
N
Br
Ar
ArAr=
CF3
CF3
Angew. Chem. Int. Ed. 2003, 42, 3796
O
CO2tBu
O
CO2tBuO
CO2tBu
96 yield%85 ee%
88 yield%92 ee%
94 yield%97 ee%
90 yield%95 ee%
Other Alkylation
N
HN
O
O
OtBu
cat(2mol%)RX(1.1eq)
toluene/50% base aq.0oC
N
HN
O
O
OtBu
R
N
Br
Ar
Ar Ar=
But tBu
tBu
tBu
97 yield%97 ee%
Angew. Chem. Int. Ed. 2003, 5, 42
N
O
N
N
O
NH
N
O
N
R
OMe
PG
NH
PG
H2N
R1
O
R3H2N
R2
OH
R3H2N
R2
R4
J. AM. CHEM. SOC. 2005, 127, 5073
N
O
CO2tBu
Bocn
n=1,2
cat (1mol%)R1Br(1.2eq)
sat. K2CO3, o-xylene0oC
N
O
CO2tBu
Bocn
n=1,2
R1
84-99 yield%87-95 ee%
N
Ar
Ar
Br-Ar=
CF3
CF3
O.L. 2004, 7, 191
N
Ar
Ar
Br- Ar=
CF3
CF3
O
OO
R1 R2Brcat. (1mol%)
toluene, CsCO3
0oCO
OO
R1
R2
91 yield%91 ee%
Adv. Synth. Catal. 2006, 348, 1539
NO
O
O
Ar2 Ar1cat (1mol%)RBr (1.2eq)
25% KOH aq TBME-20oC-0oC
NO
O
O
Ar2 Ar1
R
70-87 yield%87-99 ee%
>90 ee%
Angew. Chem. Int. Ed. 2006, 45, 3839
Ph2CN CO2tBu
cat. (1mol%)
18-crown-6 (1mol%)toluene-KOH aq 0oC
R1 Br
Me kinetic resolution
R
fast
S
slow
R1 CO2tBu
Me
NCPh2
syn
R1 CO2tBu
Me
NCPh2
ant
N
Ar
Ar
Br-Ar=
F3C CF3
CF3
CF3
>95:5 syn/ant90 de%
O.L. 2007, 9, 3945
O
N CO2tBu
RXcat (1mol%)
CsOH, toluenelow temperture
O
N CO2tBu
R
3,5_F2C6H3
3,5_F2C6H3
N+Bu
Bu
T.L. 2008, 49, 5461
For pioneering work :Jew, S.-s. Org. Lett. 2005, 7, 1557. Angew. Chem., Int. Ed. 2004, 43, 2383
N
O
N
R
R1R2
R1
R2
CO2tBuR3Br
PTC (2mol%)
base, mesitylene -20oC
R1
R2
CO2tBuR3
R1= TMS, Ar, aliphatic, olefin
R2=Et, Me
R3=ArCH2OtBu
O
3,4,5_F2C6H3
3,4,5_F2C6H3
N+Bu
Bu
Angew. Chem. Int. Ed. 2009, 48, 5014
conclusion
• design new powerful PTC catalyst which contain C2-Symmetry which is different from the cinchona skeleton
• expand the application of the PTC in varieties of chemcal reaction
Thank you for your attention!
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