01637nas a2200205   4500008004100000022001400041245007300055210006900128260000900197300001400206490000700220520097800227100001901205700002201224700002101246700001701267700002401284700001901308856010401327       2026                        eng d  a0022-326300aNHC-based diazo compounds: pathways to N2 liberation or dimerization0 aNHCbased diazo compounds pathways to N2 liberation or dimerizati  cMAY   a6566-65720 v913 a<p>
	We previously reported the C-H bond cleavage of Me3SiCHN2 by 1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene (5-SIPr) to form 1. In this article, we showed that electron-poor diamido carbene 5-tBuDAC also cleaves the C-H bond of Me3SiCHN2 to form 5, unlike its ring-expanded congener 6-DippDAC, which forms N-heterocyclic methylene hydrazine. The divergence of reactivity has been explained with the help of DFT studies. Further divergence occurs when 1 and 5 were reacted with HCl. While dimerization was observed with 5-SIPr based diazoalkane to give quinoidal tetrazine (2), N2 elimination occurs from 5-tBuDAC based diazoalkane to afford 7 and 8. This contrasting behavior highlights the subtle yet profound influence of the N-heterocyclic carbene (NHC) framework on the fate of the diazo units. DFT studies shed light about the mechanism for the formation of 2 as well as reveal that N2 elimination is thermodynamically favored over dimerization for 5.</p>
1 aBalayan, Kajal1 aTiwari, Prabhakar1 aSharma, Himanshu1 aVanka, Kumar1 aGonnade, Rajesh, G.1 aSen, Sakya, S.  uhttps://library.ncl.res.in/content/nhc-based-diazo-compounds-pathways-n2-liberation-or-dimerization