01443nas a2200157   4500008004100000022001400041245014800055210006900203260000900272300001600281490000600297520080300303100002401106700002601130856012901156       2024                        eng d  a2470-134300aC-H functionalization of imidazo[1,5-a]pyridines: a metal-free approach for methylene insertion to access C(sp2)-C(sp3)-H-C(sp2) bond formation0 aCH functionalization of imidazo15apyridines a metalfree approach  cDEC   a49071-490800 v93 a<p>
	Formaldehyde has been used as a solvent and a source of carbon to insert a methylene group for bridging two imidazo[1,5-a]pyridine molecules without using any metal catalysis. This strategy has been extended on other alkyl-, aryl-, and heteroaryl aldehydes as well. This C(sp2)-C(sp3)-H-C(sp2) bond forming reaction proceeds via C(sp2)H functionalization of imidazo[1,5-a]pyridine and was applied on a wide range of substrates offering moderate to good yields of methylene-bridged/inserted bis-imidazo[1,5-a]pyridines. Most importantly, as an application, the bis-heteroarene product has been demonstrated as a ligand. The ligand-like behavior of bis-imidazo[1,5-a]pyridines has been demonstrated as an extension of current methodology. This reaction works well at the gram scale level.</p>
1 aMahajan, Shivangani1 aSawant, Sanghapal, D.  uhttps://library.ncl.res.in/content/c-h-functionalization-imidazo15-apyridines-metal-free-approach-methylene-insertion-access