Synthesis and conformational features of sym ð?‘?,ð?‘?',ð?‘?"-triarylguanidines

Journal of Chemical Sciences

Kanniyappan Gopi¹  Brijesh Rathi¹  Natesan Thirupathi1¹ 

[1] Department of Chemistry, University of Delhi, Delhi 110 007$$

关键词: Symð?‘?;    ð?‘?';    ð?‘?"-triarylguanidines;    organocatalysts;    ð?‘?-donor ligands;    conformations;    noncovalent interactions;    AM1 calculations.;   

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

A one pot reaction involving sym 𝑁,𝑁'-diarylthiourea and the respective arylamine in the presence of aq. KOH in nitrobenzene at ≥ 105°C afforded sym 𝑁,𝑁',𝑁"-triarylguanidine in fair to good yield and the products have been characterized. Sym 𝑁,𝑁',𝑁"-tri(4-tolyl)guanidine possesses (7) anti-anti conformation, sym 𝑁,𝑁',𝑁"-tri(2-tolyl)guanidine (8) and sym 𝑁,𝑁',𝑁"-tris(2,4-xylyl)guanidine (11) each possess anti-anti 𝛼 𝛽 𝛼 conformation whereas sym 𝑁,𝑁',𝑁"-tris(2-anisyl)guanidine possesses (9) syn-anti 𝛼 𝛽 𝛽 conformation as determined by single crystal X-ray diffraction data. The observed conformations appear to result from a subtle balance between steric factor associated with the aryl substituent and multiple electronic factors namely 𝑛-𝜋 conjugation/negative hyperconjugation and non-covalent interactions in the crystal lattice.

【 授权许可】

Unknown