2,3-diazobicyclo[2.1,1]hexane cage

[Anders Hoveland]

I found a mention to 1,2-diazetidine-1,2-di-N-oxides, which seems potentially interesting. Oxidizing polynitrogenous rings can actually increase stability of the molecule. I would be very interested in 1,3-diazo bridge substituted cyclobutane cages, if they exist. (with a formula C4H6N2).

The name for the cage would be 2,3-diazobicyclo[2.1,1]hexane.
The structure of bicyclo[2.1,1]hexane can be seen here:
elchem.kaist.ac.kr/jhkwak/OkanaganPdb97/nomenclature/pdb/al0059.gif
(the two carbon atoms connected to 3 other carbons are in the 1- and 4- positions.
The 2- and 3- positions are in the ethylene (--CH2CH2--) group which bridges the 1- and 4- positions.
The 5- and 6- positions are in the methylene bridges (--CH2--))
The molecule could best be described by plain text as:
.....CH2CH2
...../......l
HC-CH2-CH
...l......./
.....CH2

"A novel and efficient method for the synthesis of 1,2-diazetidines"
Wei Miaoa, Weiliang Xua, Zhiliu Zhanga, Rujian Ma, Shu-Hui Chena, Ge Li

Summary : A novel and efficient method has been developed for the preparation of racemic or optically pure 1,2-diazetidine from 1-(1-hydroxy-propan-2-yl)hydrazine-1,2-dicarboxylate under very mild conditions with excellent yield.

Basically, HOCH2CH(R)--N(CO2H)--NH(CO2H) either undergoes a Mitsunobu reaction, or reacts with methanesulfonyl chloride CH3SO2Cl. I think the later option is very similar to the Mitsunobu reaction, because
I found an image for EtOCONHN(SO2CH3)CO2Et (there are not any N--O bonds in the structure),
which can be seen here: journals.iucr.org/e/issues/2007/04/00/hg2206/hg2206contents.gif

Then the intermediate is reacted with a base.
Apparently this reaction produces the diazetidine derivitive (R)C2H3N2(CO2H) in 85-96% yield.

This article: www.ncbi.nlm.nih.gov/pubmed/8103389 suggests that 1,2-diazetidine-1,2-di-N-oxides exist, although I am not sure how stable they are. This has an oxygen atom on each nitrogen atom.

One would therfore wonder whether 1-hydroxy-2-hydrazino-cyclobutane could similarly undergo a Mitsunobu reaction to form 2,3-diazobicyclo[2.1,1]hexane. (with a diazo bridge connected to the 1- and 3- positions of the cyclobutane ring, forming a caged molecule.

Alternatively, starting with 1,3-diamino cyclobutane...

upload.wikimedia.org/wikipedia/commons/c/cf/SulfonamideSynthesisfromSO2.png
www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv6p0078

[Anders Hoveland]

Here is the picture of the basic cage structure.

Attachments:

[Anders Hoveland]

I am envisioning two nitro groups on each of the two carbon atoms not bonded to a nitrogen atom in the above picture. 5,5,6,6-tetranitro-2,3-diazobicyclo[2.1,1]hexane, which will now be abbreviated NDZBH for the purpose of this forum. The molecular formula would be C4H2N6O8.

NDZBH would have a similar structure to TNCB, but would have greater molecular strain and contain two more nitrogen atoms, potentially making this ideal target molecule an extremely powerful explosive, perhaps with similar performance to octonitrocubane but less sensitive to impact and with a significantly easier synthesis.

Furthermore, one of the nitrogen atoms could be oxidized (adding one more oxygen atom to the molecule) for even better oxygen balance,
5-dinitro,6-dinitro-2,3-diazobicyclo[2.1,1]hexane-2N-oxide (shall be abbreviated NDZBHO).
At least for nitrotetrazole, further oxidation (forming the 2N-oxide) actually decreases the heat of formation (meaning the molecule is less energetic), but increases explosive performance by increasing density.

For more information about TNCB,
sites.google.com/site/energeticchemical/tncb