Dendrimers consisting of stilbene or distyrylbenzene building blocks synthesis and stability
摘要:
On the basis of Wittig-Homer reactions and protection group techniques compound 7 for the core and the components 9a-c and 11a-c for the dendrons were prepared and linked in the final step. The convergent synthesis yielded constitutionally and configurationally pure dendrimers (2a-c, 2a'-c') which consist of distyrylbenzene units. Their thermo-oxidative stability in the presence of air was studied by chemiluminescence and compared to the dendrimers 1 consisting of stilbene units, (C) 1999 Elsevier Science Ltd. All rights reserved.
Acetals are obtained in good to excellent yields by treatment of aldehydes and ketones with trialkyl orthoformate and the corresponding alcohol in the presence of a catalytic amount of lithium tetrafluoroborate. Due to the mild reaction conditions, this method is compatible with acid-sensitive substrates.
Carbene-Catalyzed Reductive Coupling of Nitrobenzyl Bromide and Nitroalkene via the Single-Electron-Transfer (SET) Process and Formal 1,4-Addition
作者:Yuhuang Wang、Yu Du、Xuan Huang、Xingxing Wu、Yuexia Zhang、Song Yang、Yonggui Robin Chi
DOI:10.1021/acs.orglett.6b03792
日期:2017.2.3
A carbene-catalyzed reductive 1,4-addition of nitrobenzyl bromides to nitroalkenes is disclosed. The reaction proceeds via a carbene-enabled single-electron-transfer process that generates radicals as key intermediates. The present study expands the potentials of carbene catalysis and offers unusual transformations for common substrates in organic synthesis.
Zinc triflate: A mild and efficient catalyst for deprotection of tetrahydropyranyl ethers
作者:R. Srinivasulu、P. V. V. Satyanarayana、K. Ravi Kumar
DOI:10.1134/s1070363213120384
日期:2013.12
Treatment of tetrahydropyranyl (THP) ethers with zinc triflate in methanol provides a simple and efficient process for deprotection of these ethers and the parent alcohols are obtained in excellent yields.
On the basis of Wittig-Homer reactions and protection group techniques compound 7 for the core and the components 9a-c and 11a-c for the dendrons were prepared and linked in the final step. The convergent synthesis yielded constitutionally and configurationally pure dendrimers (2a-c, 2a'-c') which consist of distyrylbenzene units. Their thermo-oxidative stability in the presence of air was studied by chemiluminescence and compared to the dendrimers 1 consisting of stilbene units, (C) 1999 Elsevier Science Ltd. All rights reserved.