31367-69-8Relevant articles and documents
Potassium isopropoxide: For sulfination it is the only base you need!
Sayah, Mahmoud,Organ, Michael G.
, p. 16196 - 16199 (2013)
PEPPSI max: KOiPr has been identified as the key ingredient for Pd-catalyzed sulfination (see scheme). Potassium is essential to keep the thiol concentration low, and isopropoxide is necessary for precatalyst activation and to break up Pd-sufide-based resting states. Together with the reactive Pd-PEPPSI-IPentCl o-picoline catalyst, this system couples profoundly deactivated partners at RT that other catalysts cannot accomplish in refluxing toluene. Copyright
Inherent Reactivity of Spiro-Activated Electrophilic Cyclopropanes
Jüstel, Patrick M.,Ofial, Armin R.,Pignot, Cedric D.,Stan, Alexandra
supporting information, p. 15928 - 15935 (2021/10/25)
The kinetics of the ring-opening reactions of thiophenolates with geminal bis(acceptor)-substituted cyclopropanes in DMSO at 20 °C was monitored by photometric methods. The determined second-order rate constants of the SN2 reactions followed linear relationships with Mayr nucleophilicity parameters (N/sN) and Br?nsted basicities (pKaH) of the thiophenolates as well as with Hammett substituent parameters (σ) for groups attached to the thiophenolates. Phenyl-substituted cyclopropanes reacted by up to a factor of 15 faster than their unsubstituted analogues, in accord with the known activating effect of adjacent π-systems in SN2 reactions. Variation of the electronic properties of substituents at the phenyl groups of the cyclopropanes gave rise to parabolic Hammett relationships. Thus, the inherent SN2 reactivity of electrophilic cyclopropanes is activated by electron-rich π-systems because of the more advanced C1?C2 bond polarization in the transition state. On the other hand, electron-poor π-systems also lower the energetic barriers for the attack of anionic nucleophiles owing to attractive electrostatic interactions.
5-halo-6-nitro-2-substituted benzoxazole compounds
-
, (2008/06/13)
Novel benzoxazole compound having, at the 2 position, a group bonding through a carbon atom having no or one hydrogen atom and introduced with a chlorine or bromine atom at the 5 position. The compounds are key intermediates useful for preparing 2-amino-5-nitrophenol derivatives which are useful as intermediates for synthesis of industrial materials, reducing agents, antioxidants, cyan-image-forming couplers and the like.
Process for preparing 2-amino-5-nitrophenol derivatives
-
, (2008/06/13)
A process for efficiently preparing 2-amino-5-nitrophenol derivatives in which benzoxazole derivatives are subjected to nucleophilic substitution reaction at the 5 position thereof to obtain corresponding benzoxazole derivatives, and the oxazole ring of the benzoxazole derivatives is then subjected to ring-opening to obtain 2-amino-5-nitrophenol derivatives. The 2-amino-5-nitrophenol derivatives are useful as industrial starting materials, reducing agents or antioxidants and intermediates for cyan-image-forming couplers.
