Advances in C–C and C–X Coupling Using Palladium–NHeterocyclic Carbene (Pd–NHC) Complexes - New Trends in Cross-Coupling: Theory and Applications - page 217

Table 4.29 C-S bond formation using [Pd(NHC)] 99c.

X SH S

99c (2 mol%)

+

R R' R R'

KOtBu, toluene, reflux

X=Br,I

R 0

Entry X R Yield (%)

1 Br 4-OMe 4-Me 94

2 Br 4-Cl 4-Me 97

3 Br 4-NO 2 4-Me 88

4 Br 4-Me 4-MeO 75

5 Br 4-Me 4-Me 86

6 Br H 2-Naphthalenethiol 77

X SH S

100 (2 mol%)

+

R R

KOtBu, toluene, 100°C

NN

X=Cl,Br

S S

S S

Cl Pd Cl

MeO S

N

X=Cl:56%
X = Br : 94%

X=Cl:68%
X=Br:75%

X=Br:94%

S

S

[Pd(SIPr)(pyridinyl)Cl 2 ]
100

H 2 N

OH

X =Br: 90% X =Br: 79%

X

100 (2 mol%)

SH

S

+

R

KOtBu, toluene, 100°C R

X=Cl,Br

S OMe

S S

S S

MeO F

X = Cl: 43%
X=Br:81%

X=Br:86% X=Cl:50% X=Br:84%

S S

X=Cl:47%
X = Br : 91%

Scheme 4.69 C-S bond formation using [Pd(SIPr)(pyridinyl)Cl 2 ](100).

for the coupling of aryl halides with aryl thiols (Scheme 4.70). Both bromides
and chlorides were reactive, including sterically and electronically dis-
favoured analogues. Of note, alkanethiols were also found to be suitable