Thermal Stability of Substituted Borazoles¹

Preparation and Properties of Imido Intermediates (Imidogens)

“…An analogous reaction is the photochemical decomposition of azine monoxides (145). The formation of phenylimidogen has been proposed to account for the thermal decomposition of hexaphenylborazole (LXXI) (218) and for the decomposition of N-chloro-…”

The Structural Chemistry of N‐Monolithium Borazines

“…Solvents were dried by conventional methods. NMR: Bruker ACP 200 ( 1 H, 7 Li, 11 B, 13 C), Jeol GSX 270 ( 1 H, 7 Li, 11 B, 29 Si) or Jeol EX 400 ( 1 H, 11 B, 13 C). Standards: C 6 D 6 , SiMe 4 , external 1 m aqueous LiCl, BF 3 ·OEt 2 .…”

“…The solid that formed was later isolated and characterized as NH 4 Cl (3-5 % based on MeBCl 2 ). The 11 2 , 48.9 ppm [MeB(NHBMe) n -NHSiMe 3 ] and 63.0 ppm (MeBCl 2 ) in a ratio of 1:12:4:3:2:1). The solution was then heated to reflux (water-cooled condenser) for 4 to 10 d until the 11 B NMR spectrum showed only the signal of 1 at δ = 36 ppm.…”

“…All volatile material was removed in an oil-pump vacuum at 20°C from 5 mL of the reaction solution and the residue dissolved in 1 mL of C 6 D 6 . This solution showed 11 Reaction of 1 with tBuLi: Compound 1 (0.97 g, 7. 8 mmol) was dissolved in hexane (35 mL) and the solution cooled to -78°C.…”

Synthesis and Reactions of Borazines

“…When heated to 120 °C, this adduct loses hydrogen and rearranges to yield corresponding borazine 18 (Scheme 16, no yield reported). 58 Scheme 16 Synthesis of an N-trifunctionalized borazine from diphenylketimine-borane adduct 58 Schaeffer and Anderson's protocol (Scheme 3) 32 was applied, though in a simplified fashion, to the reaction of other alkylammonium halides or arylammonium halides with LiBH 4 at a temperature of 90 °C leading to the formation of the corresponding N-trialkylborazines or N-triarylborazine, such as: N-trimethylborazine (4), N-triethylborazine (16), N-tripropylborazine, N-triisopropylborazine, and N-triphenylborazine (Scheme 17). 59 Scheme 17 Synthesis of N-trisubstituted borazines from LiBH 4 and alkylammonium chloride 59 Myakishev, and later Volkov described a mechanochemical variant of this process.…”