Role of the Bromide on the Hydrodebenzylation of 2,4,6,8,10,12‐Hexabenzyl‐2,4,6,8,10,12‐hexaazaisowurtzitane (HBIW)

Abstract

The catalytic hydrogenolysis of 2,4,6,8,10,12‐hexabenzyl‐2,4,6,8,10,12‐hexaazaisowurtzitane (HBIW) over Pd‐based catalysts in the ternary solvents of acetic anhydride, bromobenzene (PhBr) and N, N’‐dimethylformamide (DMF) was the key step for producing 2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (HNIW or CL‐20). However, the role of the bromobenzene is still allusive. Herein, Pd/graphite carbon nitride nanosheets (g‐C3N4 NS) was used in the hydrogenolysis of HBIW under the atmospheric pressure, and exhibited a yield of 80 % as well as a faster debenzylation rate than Pd/C. By the virtue of the kinetic study, the effect of the bromide, solvent and proton on the debenzylation rate was investigated and discussed. The bromide worked as a co‐catalyst to promote the desorption of the product of the hydrogenolysis from the surface of the palladium nanoparticle. The observation benefits for elucidating the reaction mechanism and may inspire the design of the novel catalysts for the hydrogenolysis of HBIW.

Synthesis of magnetic UiO-66-NH2@EDTA-GO and mechanism study of simultaneous adsorption of Pb(ii) and organic dyes from water

“…[62][63][64] As for GO, absorption peaks were observed at 1722.3 cm −1 and 1621.9 cm −1 , which can be attributed to the stretching vibrations of carboxyl groups (-COOH) and -CC-. In the spectrum of EDTA-GO, peaks were observed at 1320.3 cm −1 for C-N stretching vibrations, 65,66 1707.2 cm −1 for the CO stretching vibration of -COOH, 67 and 3027.5 cm −1 for the aromatic C-H stretching motion. The appearance of these characteristic peaks confirms the successful synthesis of EDTA-GO.…”

Condensation of Benzyl Carbamate with Glyoxal in Polar Protic and Aprotic Solvents

“…All the commercial synthetic processes of CL-20 involve the catalytic reductive debenzylation of HBIW to 4,10-dibenzyl-2,6,8,12-tetraacetyl-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.0 3,11 .0 5,9 ]dodecane (4,10-dibenzyl-2,6,8,12-tetraacetyl-2,4,6,8,10,12-hexaazaisowurtzitane, TADBIW) (Scheme 1) [15,23]. The reduction uses a Pdcontaining catalyst in the presence of acetic anhydride and a bromine source [91]. Despite the high yields of TADBIW (80-90%) [92][93][94][95], this stage is the most considerable contributor to the cost of CL-20.…”