Optimization of reaction conditions^a.

Entry	Diboron(4)	Base	Solvent	Conversionb
1	B2pin2	MeOK	THF	17%
2	B2neo2	MeOK	THF	63%
3	B2eg2	MeOK	THF	96%
4	B2eg2	MeONa	THF	78%
5	B2eg2	Cs2CO3	THF	91%
6	B2eg2	Cs2CO3	THF	73%
7	B2eg2	Cs2CO3	MeCN	71%

^aReaction conditions: 4-PhPy (0.36 mmol, 1 equiv.), diboron(4) (1.1 equiv.), base (1.1 equiv.), MeOH (11 equiv.), solvent (2 mL), sealed tube, 30 °C for 4.5 h.

^bDetermined by ¹H NMR analysis. B₂pin₂ = bis(pinacolato)diboron; B₂neo₂ = bis(neopentyl glycolato)diboron; B₂eg₂ = bis(ethylene glycolato)diboron.