 The Kröhnke synthesis can also employ alkyl and vinyl substituents giving moderated to good yields as well.Due to its broad scope, the Kröhnke method has seen wide applicability to for the synthesis of bipyridines (16), terpyridines (17), quaterpyridines (18) and even up to septipyridines (19) as shown below.The Kröhnke method is featured in a solvent-free synthesis of triarylpyridines that proceeds via a homo-coupling of two diaryl substituted α, β-unsaturated carbonyl compounds.