To test the limits of the NHC ligand-controlled selectivity, chloropyridyl triflates were examined as substrates for the SM reaction (Table 3). All else being equal, the reactivity of pyridine C−X bonds toward Pd(0) generally follows the order C2 > C4 > C3/C5. We were interested in whether the strong electronic biases of this substrate class would erode the NHC ligand-controlled selectivity. Furthermore, the mechanism of oxidative addition of chloropyridines at Pd(0) may be different from that of chloroarenes, which could affect selectivity. The results of the reactions of 34 and 35 with Pd/SIMes indicate that selectivity for triflate using SIMes remains ligand-controlled (entries 1−2). Selective cross-coupling at triflate of substrate occurs even though pyridine electronics should favor reaction at the C2−Cl bond. However, interestingly the selectivity with SIPr is less predictable. Selective Pd/SIPr-catalyzed cross-coupling at chloride only occurs with35, the substrate that is most heavily electronically biased for reaction at C−Cl. With this substrate, cross-coupling at C2−Cl takes place preferentially over reaction at C5−OTf to give35a(entry 3). However, with substrates36,34, and37, Pd/SIPr-catalyzed cross-coupling takes place selectively at C−OTf (entries 4−6). The results with substrate36are particularly intriguing: reaction at chloride should be expected based on both the electronic bias of the pyridine ring and SIPr’s usual preference for reaction at chloride. However, coupling takes place selectively at C4−OTf. Further study is needed to understand these incongruous results and their possible relationship to differences in the mechanism of oxidative addition of chloroarenes compared to chloropyridines.