Palladium-Catalyzed Carbonylative Coupling and C–H Activation - New Trends in Cross-Coupling: Theory and Applications - page 481

Pd (0) metal

Decomposition
to metallic Pd

Pd (II) (CO) n

Ligand competition
by CO

CO

Pd (II)

Specific
oxidant
required

RCH

Poor reactivity of
C-H bond

Pd (0)

Pd-CR

RCCO(Nuc)

CO

PdCOCR

Nuc

Figure 10.2 Palladium-catalysed oxidative carbonylations.

10.2 Carbonylative Heck Reactions
In the late 1960s, Heck and co-workers developed several coupling reactions of
arylmercury compounds in the presence of either stoichiometric or catalytic
amounts of palladium salts. 4a-g Based on this work, in 1972 Heck and Nolley
described a protocol for the coupling of iodobenzene with styrene, which today
is known as the Heck-Mizoroki reaction. 4h Two years later, Heck and co-
workers described their pioneering work on palladium-catalysed alkoxy-,
hydroxy- and aminocarbonylation of aryl iodides and bromides, which is
nowadays called the Heck carbonylation reaction. 1 The first palladium-
catalysed copolymerization of CO with olefins was described in 1982, 4i and
consequently carbonylative coupling reactions with alkenes were reported soon
after. Notably, it was Negishi and Miller who discovered the first two examples
of the intramolecular carbonylative Heck reaction of 1-iodopenta-1,4-dienes by
applying stoichiometric amounts of palladium. 5 The product 5-methylenecy-
clopent-2-enones were produced in moderate yields (Scheme 10.1). However,
using 1a-e (Scheme 10.2) as substrates, no desired carbonylation products
were detected, although complete conversion of starting material occurred.
Presumably, polymerization of 1a-e (Scheme 10.2) took place. 6
The same group improved the methodology 2 years later, 6 where they ap-
plied 1a-e as starting materials using catalytic amounts of palladium salts in