Reactions of 1,3,5-triazine with organolithium compounds yielding 1,4-dihydrotriazines or the ring-opened products, a 3-lithio-1,3,5,7-tetraazaheptatriene or -1,3,5-triazaheptatriene†

Abstract

1,3,5-Triazine 1 reacts with the lithium alkyl LiR′ (R′ = CHR₂, CH₂R, Me, Buⁿ or Ph; R = SiMe₃) to give 1,4-adducts which on hydrolysis yield the first simple 1,4-dihydrotriazines; however, 1 with LiNR₂ or LiCR₃(thf)₂ gives the crystalline ring-opened 3-lithio-1,3,5,7-tetraazaheptatriene 5 or -1,3,5-triazaheptatriene 6 [Li{RNC(H)NC(H)NC(H)ER}]_n(µ-L) (E = N, n = 3 and L is absent 5, or E = CR, n = 2 and L = thf = tetrahydrofuran 6).