31
were proposed to be the active intermediates in this reaction and identified by comparison with an authentic sample. When alkynyl zinc chloride was directly used
instead of terminal alkyne, similar yield and selectivity were observed.
ArMgBr
[RuCl(C 3 S 5 )(H 2 O)(PPh 3 ) 2 ]
(0.3 mol%)
air, Et 2 O, r.t., 6 h
Ar Ar
S
Ru
S
S
S
S
Cl
OH 2
PPh 3
PPh 3
[RuCl(C 3 S 5 )(H 2 O)(PPh 3 ) 2 ]
Ar(OH) 2
Au 0.81 Pd 0.19 -chit (2 mol%)
air, Acetate buffer
30 o C, 2-34 h
Ar Ar
ArMgBr
NiL (0.1 mol%)
air, Et 2 O, r.t., 5 h
Ar Ar
NiL
S
S
S
Ni
S
O
N
N
N
O
S
ONa
RMgBr
CoCl 2 (5 mol%)
air, THF, 0 o C., 0.5-3 h
R R
R = Aryl, Alkenyl, Alkynyl
Scheme 2.41 Cobalt-, ruthenium-, gold/palladium bimetallic alloy-, and nickel-catalyzed oxidative homo-coupling of organometallic compounds
SnBu 3
R
+
SnBu 3
Pd(OAc) 2 (5 mol%)
O 2 , Benzene
r.t., 1-18 h
R
Ph
Ph
OH
5
94% a
72% a
84%
75%
73%
a: PdCl 2 (MeCN) (5 mol%)/DMF
Scheme 2.42 Pd-catalyzed oxidative cross-coupling of vinylstannanes and allylstannane
2 Transition Metal-Catalyzed Oxidative Coupling Involving Two Organometallic…