Pd(0)-Catalyzed Carboiodination: Early Developments and Recent Advances - New Trends in Cross-Coupling: Theory and Applications - page 302

Table 7.4 Screening of PdL 2 catalysts for intramolecular carboiodination.

I vi a

Pd L 2 (5 mol%)
PhMe, 90

I

[Pd ]

° C, 16 h

I

O

O O

7.41 7.42 7.43

QPhos

P t Bu 2

Fe

Ph Ph

Ph Ph

Ph

Entry Ligand Yield (%)

82 (95) a 1 QPhos

P t Bu 3 2 61

PhP(P t Bu 3 ) 2 3 76

4 PCy 3 0

5 P(o-tol) 3 0

a Reaction run with 2.5 mol% Pd(QPhos) 2 at 100 1C for 4 hours.

I

I

Pd(QPhos) 2 (2.5 mol%)
PhMe, 100 ° C, 4-16 h

R R

O

O

I

Ph

I

MeO 2 C I

O

O

O

92% 94% 86%

I

I

I

O

NBn

Ts

Ts

O

93% 97% 93%

Scheme 7.25 Scope of Pd-catalyzed carboiodination.

and bromides in the reaction was unsuccessful, suggesting that C-Cl and
C-Br reductive elimination may be more dicult. The proposed mechanism
of the reaction involves oxidative addition to the aryl iodide, olefin insertion
and unprecedented C-I reductive elimination from an alkylpalladium(II)
species to regenerate the active Pd(0) catalyst.