Ein neuer abbau des tetrazolrings acetylene aus substituierten 5-methyl-1H-tetrazolen

Recent advances in alkylidene carbene chemistry

“…Like diazoalkenes, tetraazafulvenes are unstable and it is necessary to generate them in situ from more stable precursors. The use of tetrazoles to generate alkylidene carbenes was first reported by Behringer in 1966, 37 but further development of this chemistry has only occurred in recent years.…”

Dehydrative Fragmentation of 5-Hydroxyalkyl-1H-tetrazoles: A Mild Route to Alkylidenecarbenes

“…In this context, we were intrigued by a rarely cited report from Behringer regarding the thermolysis and rearrangement of 5-hydroxy(diarylmethyl)-1 H -tetrazoles and related derivatives 1 to form diarylalkynes 4 (Scheme 1). 9 In this case, dehydration of 1 (X = OH) was proposed to generate unstable tetraazafulvene intermediate 2 which undergoes conversion to the observed products through extrusion of two moles of dinitrogen and rearrangement of the resulting alkylidenecarbene 3 . 10,11 …”

Novel tetrazol‐5‐germavinylidenes with triplet monomeric, normal, and abnormal forms studied using DFT method

“…Reactive intermediates with the >C═Ge: functional group are called germavinylidenes. Synthesis of free (monomeric), stable germavinylidene has received much attention in the past two decades . Actually, monomeric germavinylidenes has rarely been found.…”

“…Synthesis of free (monomeric), stable germavinylidene has received much attention in the past two decades. [1][2][3][4][5] Actually, monomeric germavinylidenes has rarely been found. Their low stability could be due to the reduced steric protection at the low-coordinate metal center, which leads to oligomerization.…”

“…The NBO analyses including atomic charges (e) for normal (1) and abnormal(2) vinylidene germylenes, calculated at B3LYP/6-311++G ** level of theory −0.23 −0.43 −0.03 −0.03 −0.43 H(T) 0.07 −0.08 −0.39 −0.03 −0.03 −0.40 1 OH(S) 0.60 −0.36 −0.04 −0.02 −0.02 −0.04 1 OH(T) 0.04 −0.14 0.07 −0.03 −0.03 0.07 1 SH(S) 0.48 −0.26 −0.48 −0.00 −0.00 −0.48 1 SH(T) 0.15 −0.07 −0.43 −0.01 −0.01 −0.−0.25 −0.36 −0.08 −0.06 −0.23 2 CN(T) 0.61 −0.13 −0.34 −0.06 −0.15 −0.24 2 CF3(S) 0.62 −0.29 −0.40 −0.10 −0.04 −0.26 2 CF3(T) 0.60 −0.14 −0.37 −0.09 −0.20 −0.The π-interaction between carbon and the adjacent nitrogens S C H E M E 3 Electron delocalizations through seven sets of possible canonical forms (I-VII) for our (a) normal 1 R and (b) abnormal 2 R germavinylidenes normal 1 R isomer is more aromatic than its corresponding abnormal, 2 R . The resonance hybrid structures (Scheme 3) for germavinylidenes reveal the electronic effects on (a) normal 1 R and (b) abnormal 2 R isomers.…”