Bridge-Chlorinated Bicyclo[1.1.1]pentane-1,3-dicarboxylic Acids

0503719 - ÚOCHB 2020 RIV US eng J - Journal Article
Kaleta, Jiří - Rončević, Igor - Císařová, I. - Dračínský, Martin - Šolínová, Veronika - Kašička, Václav - Michl, Josef
Bridge-Chlorinated Bicyclo[1.1.1]pentane-1,3-dicarboxylic Acids.
Journal of Organic Chemistry. Roč. 84, č. 5 (2019), s. 2448-2461. ISSN 0022-3263. E-ISSN 1520-6904
R&D Projects: GA ČR(CZ) GA17-10832S; GA MŠMT(CZ) 7AMB16FR038
Institutional support: RVO:61388963
Keywords : molecular rotors * surface inclusion * cage compounds
OECD category: Organic chemistry
Impact factor: 4.335, year: 2019
Method of publishing: Limited access
https://pubs.acs.org/doi/10.1021/acs.joc.8b02780

Radical chlorination of bicyclo[1.1.1]pentane-1,3-dicarboxylic acid is highly selective, and up to four chlorine atoms can be introduced relatively easily without damage to the strained bicyclic cage. Combined with hydrodechlorination with TMS3SiH, direct chlorination provides access to five of the 15 possible chlorinated diacids. Their configuration has been established by X-ray diffraction. Their pKa values have been measured by capillary electrophoresis and calculated at the B3LYP-D3BJ/6-311+G(d,p)-level. The results are in good agreement and reflect the expected trend, from 2.78 +/- 0.08 and 4.14 +/- 0.10 in the parent to 1.07 +/- 0.03 and 2.31 +/- 0.03 in the tetrachlorinated diacid. Strain energy relative to the parent diacid was calculated for all 15 chlorinated diacids and shows a dramatic increase with successive chlorination, due to nonbonded Cl-Cl repulsions.
Permanent Link: http://hdl.handle.net/11104/0296693