TY - JOUR

T1 - Mesomeric Betaines Based on Adamantylated 1,2,4-Triazolo[4,3-a]pyrimidin-5-ones

T2 - Synthesis, Structure and Conversion into Anionic N-Heterocyclic Carbenes

AU - Sheina, Ekaterina S

AU - Shestakova, Tatyana S

AU - Deev, Sergey L

AU - Khalymbadzha, Igor A

AU - Slepukhin, Pavel A

AU - Eltsov, Oleg S

AU - Novikov, Alexander S

AU - Shevyrin, Vadim A

AU - Charushin, Valery N

AU - Chupakhin, Oleg N

N1 - © 2023 Wiley-VCH GmbH.

PY - 2023/3/1

Y1 - 2023/3/1

N2 - The C-N coupling of 1,2,4-triazolo[1,5-a]pyrimidin-7-ones with 1-adamantanol/1-bromoadamantane leads to 1,2,4-triazolo[4,3-a]pyrimidinium-5-olates, which are represented as mesomeric betaines (MBs). The formation of MBs involves not only N-alkylation of heterocyclic framework but also the rearrangement leading to a change in the type of fusion between pyrimidine and 1,2,4-triazole fragments. The structures of the obtained products were confirmed by the X-ray analysis and measurements of 13 C-13 C (JCC ) coupling constants in the 1D 13 C NMR spectra of selectively 13 C-labeled samples. Treatment of the betaines with lithium bis(trimethylsilyl)amide (LiHMDS) gave anionic carbenes, which were detected by 13 C NMR spectroscopy and were trapped by reactions with phenyl isothiocyanate and sulfur. Density functional theory (DFT) and the quantum theory of atoms in molecules (QTAIM) analyses allowed for an insight into the electronic structure of the obtained betaines and N-heterocyclic carbene derivatives.

AB - The C-N coupling of 1,2,4-triazolo[1,5-a]pyrimidin-7-ones with 1-adamantanol/1-bromoadamantane leads to 1,2,4-triazolo[4,3-a]pyrimidinium-5-olates, which are represented as mesomeric betaines (MBs). The formation of MBs involves not only N-alkylation of heterocyclic framework but also the rearrangement leading to a change in the type of fusion between pyrimidine and 1,2,4-triazole fragments. The structures of the obtained products were confirmed by the X-ray analysis and measurements of 13 C-13 C (JCC ) coupling constants in the 1D 13 C NMR spectra of selectively 13 C-labeled samples. Treatment of the betaines with lithium bis(trimethylsilyl)amide (LiHMDS) gave anionic carbenes, which were detected by 13 C NMR spectroscopy and were trapped by reactions with phenyl isothiocyanate and sulfur. Density functional theory (DFT) and the quantum theory of atoms in molecules (QTAIM) analyses allowed for an insight into the electronic structure of the obtained betaines and N-heterocyclic carbene derivatives.

UR - https://www.mendeley.com/catalogue/41ec53f8-9a2b-3aac-84ed-0907ed05ad62/

U2 - 10.1002/asia.202201306

DO - 10.1002/asia.202201306

M3 - Article

C2 - 36662627

VL - 18

SP - e202201306

JO - Chemistry - An Asian Journal

JF - Chemistry - An Asian Journal

SN - 1861-4728

IS - 5

ER -