1 3
Topics in Current Chemistry (2019) 377:38
as the amine catalyst, which provided optically active morphan derivatives containing α-carbonyl stereocenter 130. The α-arylated compounds were afforded
126
N
H
Ar
Ar
OH
R
1
H
O
9
+
128
N
H
Ar
Ar
R
1
O
H
TFA (20 mol%), MeCN, HFIP
PPh 3 AuCl (5 mol%), 50
o
C
N
H
Ar
OTBDMS
Ar
127 (20% mol)
Ar = 3,5-bis(trifluoromethyl)phenyl
R
R
128a R
1 = Me, R = H, Ar = Ph, 60% yield, 82% ee
128b R
1
= H, R = H, Ar = Ph, 63% yield, 72% ee
128c R
1
= H, R = 6-OMe, Ar = Ph, 69% yield, 72% ee
128d R
1
= Me, R = 5-Cl, Ar = Ph, 57% yield, 72% ee
Scheme 26 Asymmetric α-arylation of aldehydes and 2-Indolylmethanols
129
N
130
Proline 4 (10 mol%), Pd(OAc) 2 (5 mol%)
PPh 3 (12 mol%), AcOH (1.5 equiv.)
K 3 PO 4 (1.5 equiv.), MeOH, 85
o
C
R
1
R
1
130a R
2 = Bn, X = Br, 91% yield, 97% ee
130b R
2 = Bn, X = I, 83% yield, 93% ee
130c R
2 = Bn, X = Cl, 50% yield, 60% ee
O
X
R
2
N
R
2
H
O
H
131
134
Pd(OAc) 2 (5 mol%), 1,4-dioxane, 85
o
C
O
R
2
Y
Br
O
R
2
Y
H
R
1
R
1
n-Pr
P N
n-Pr
N
H
CO 2 H
132
133
Y = O: (S,S)-BDPP (5 mol%)
132 (10 mol%), K 3 PO 4 (1.5 equiv.);
Y = NTs: Pyrrolidine 14 (10 mol%),
NaOAc (1.0 equiv.), 133 (10 mol%)
O
H
NTs
H
Cl
134a 98% yield, 86% ee
O
H
NTs
H
134b 85% yield, 97% ee
F
O
H
O
H
134d 72% yield, 88% ee
O
H
O
H
134e 67% yield, 90% ee
Cl
O
Me
NTs
H
134c 84% yield, 91% ee
O
Me
O
H
134f 64% yield, 90% ee
Scheme 27 Combined palladium and amine catalyzed enantioselective α-arylative desymmetrization of
cyclohexanones 129 and of cyclobutanones 131
Reprinted from the journal
19