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Design of a Nanoscale Ni Catalyst for Debenzylation Reactions via Hydrogenative C–N Bond Cleavage. Catal Letters 2022. [DOI: 10.1007/s10562-022-04196-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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Deactivation and Regeneration of Palladium Catalysts for Hydrogenation Debenzylation of 2,4,6,8,10,12-Hexabenzyl-2,4,6,8,10,12-Hexaazaisowurtzitane (HBIW). Catalysts 2022. [DOI: 10.3390/catal12121547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (HNIW, also known as CL-20) is an important energetic compound. As one of the representatives of the third generation of energetic materials, it has an excellent performance, providing broad application prospects for the development of new weapons and equipment. The synthesis of CL-20 is usually obtained from 2,4,6,8,10,12-hexabenzyl-2,4,6,8,10,12-hexaazaisowurtzitane (HBIW) through two catalytic hydrogenolysis and debenzylation reactions, followed by nitration. The most critical step is the hydrogenolysis debenzyl-acetylation process of HBIW because this process requires a large amount of expensive palladium-based catalyst, and the catalyst is completely deactivated after one use. In response to this problem, there is no suitable solution at present, resulting in the high cost of the entire synthesis process. Therefore, reducing the production cost of CL-20 by increasing the catalyst stability is one of the current research priorities. By using AAS, XRD, XPS, TEM, BET, TG and other characterization techniques, the reasons for catalyst deactivation were explored. Studies have shown that the main reason for catalyst deactivation is that a large number of blockages accumulate in the pores of the catalyst after the reaction, which greatly weakens the transfer of the reactant HBIW, intermediate substances, and product 2,6,8,12-tetraacetyl-4,10-dibenzyl-2,4,6,8,10,12-hexaazaisowurtzitane (TADBIW) in the catalyst pores, and the blockage may block the active site of the catalyst. A regeneration treatment method for catalyst deactivation was developed. This method uses chloroform and glacial acetic acid as reagents, which, when combined with stirring and ultrasonic operation, finally restores the activity of the Pd(OH)2/C catalyst. The BET and TG parameters of the regenerated catalyst indicate that catalyst textural and structural properties have greatly recovered, indicating that this treatment method can remove the blockages in the catalyst pores.
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TiO2 supported Pd nanoclusters with surface defects toward highly efficient hydrogenation of quinone to hydroquinone under mild conditions. MOLECULAR CATALYSIS 2022. [DOI: 10.1016/j.mcat.2022.112521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Acid-Catalyzed Condensation of Benzamide with Glyoxal, and Reaction Features. Molecules 2022; 27:molecules27031094. [PMID: 35164359 PMCID: PMC8838861 DOI: 10.3390/molecules27031094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/27/2022] [Accepted: 02/03/2022] [Indexed: 12/04/2022] Open
Abstract
Scholars from around the world have been attempting to simplify and cheapen the synthetic method for the promising high-energy compound CL-20 for decades. The lack of understanding of the formation mechanisms of hexaazaisowurtzitane derivatives-CL-20 precursors-is a barrier to solving the said problems. Here, we report the results from an in-depth study into the acid-catalyzed condensation between benzamide and glyoxal in a molar ratio of 2:1 in polar protic and aprotic solvents. Sixteen compounds were isolated and identified, of which eight were synthesized for the first time. A geminal diol, N,N'-(2,2-dihydroxyethane-1,1-diyl)dibenzamide, was synthesized. Two isomers of 1,2-bis(benzoylamino)-1,2-ethanediol were isolated and identified. N,N'-(1-oxoethane-1,2-diyl)dibenzamide and 2-oxo-2-[(phenylcarbonyl)amino]ethyl benzoate were produced that were likely formed due to the 1,2-hydride shift. N-polysubstituted 1,4-dioxane-2,3,5,6-tetramine was synthesized for the first time, whose structure may be of interest as a scaffold for new explosives. DMSO, THF and HCOOH were found to be able to engage in a reaction with benzamide, or condensation products thereof, and glyoxal under acid-catalyzed conditions.
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Tang X, Zhu R, Shi T, Wang Y, Niu X, Zhang Y, Zhu J, Li W, Hu W, Xu R. Research Progress and Key Issues of Hydrodebenzylation of Hexabenzylhexaazaisowurtzitane (HBIW) in the Synthesis of High Energy Density Material Hexanitrohexaazaisowurtzitane (HNIW). MATERIALS 2022; 15:ma15020409. [PMID: 35057135 PMCID: PMC8778682 DOI: 10.3390/ma15020409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/25/2021] [Accepted: 12/29/2021] [Indexed: 01/15/2023]
Abstract
High energy density materials (HEDM) are the subject of an extensive research effort in relation to the use of these compounds as components of rocket propellants, powders, and formulations of high-performance explosives. Hexanitrohexaazaisowurtzitane (HNIW, i.e., CL-20) has received much attention in these research fields for its specific impulse, burning rate, ballistics, and detonation velocity. In this paper, the development and performances of the explosives from the first to the fourth generation are briefly summarized, and the synthesis status of the fourth-generation explosive, HNIW, is reviewed. The key issues that restrict the development of industrial amplification synthesis of HNIW are analyzed, and the potential directions of development are proposed. It is pointed out that to synthesize new and efficient catalysts is the key to making the cost-effective manufacturing of CL-20 a reality.
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Affiliation(s)
- Xiaofei Tang
- Xi’an Modern Chemistry Research Institute, Xi’an 710065, China; (X.T.); (Y.Z.); (J.Z.); (W.L.)
| | - Rui Zhu
- College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, China; (R.Z.); (T.S.); (Y.W.); (X.N.)
| | - Tianjing Shi
- College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, China; (R.Z.); (T.S.); (Y.W.); (X.N.)
| | - Yu Wang
- College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, China; (R.Z.); (T.S.); (Y.W.); (X.N.)
| | - Xiaochen Niu
- College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, China; (R.Z.); (T.S.); (Y.W.); (X.N.)
| | - Yao Zhang
- Xi’an Modern Chemistry Research Institute, Xi’an 710065, China; (X.T.); (Y.Z.); (J.Z.); (W.L.)
| | - Junchen Zhu
- Xi’an Modern Chemistry Research Institute, Xi’an 710065, China; (X.T.); (Y.Z.); (J.Z.); (W.L.)
| | - Wei Li
- Xi’an Modern Chemistry Research Institute, Xi’an 710065, China; (X.T.); (Y.Z.); (J.Z.); (W.L.)
| | - Wanpeng Hu
- College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, China; (R.Z.); (T.S.); (Y.W.); (X.N.)
- Correspondence: (W.H.); (R.X.)
| | - Ruoqian Xu
- Xi’an Modern Chemistry Research Institute, Xi’an 710065, China; (X.T.); (Y.Z.); (J.Z.); (W.L.)
- Correspondence: (W.H.); (R.X.)
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