@article {49320, title = {1,6-Conjugate addition of in situ generated aryldiazenes to p-quinone methides}, journal = {Organic \& Biomolecular Chemistry}, volume = {22}, year = {2024}, month = {JUL}, pages = {5636-5645}, type = {Article}, abstract = {

Herein we report a transition-metal free, base-mediated 1,6-conjugate addition of aryldiazenes to para-quinone methides (p-QMs). Arylhydrazines were used for the in situ generation of aryldiazenes using a base-mediated protocol in the presence of air as the oxidant. The 1,6-conjugate addition of aryldiazenes to para-quinone methides via a radical mechanism is followed by an oxidative rearrangement to furnish the desired product, arylhydrazones. Interestingly, our synthetic protocol results in the formation of an aryldiazene radical, which undergoes 1,6-conjugate addition with p-QMs to furnish the arylhydrazones.

}, issn = {1477-0520}, doi = {10.1039/d4ob00618f}, author = {Mamale, Ajay G. and Paul, Sayantan and Gonnade, Rajesh G. and Bhattacharya, Asish K.} } @article {49300, title = {Methanesulfonic acid-catalyzed friedel-crafts alkylation: towards sustainable synthesis of arylalkanes from donor-acceptor cyclopropane ketones}, journal = {Asian Journal of Organic Chemistry}, volume = {13}, year = {2024}, month = {JUL}, type = {Article}, abstract = {

We present herein Br \& oslash;nsted acid-catalyzed Friedel-Crafts alkylation of phenols with Donor-Acceptor cyclopropane ketones. The presence of the 1,4-diphenyl butan-1-one and 1,3-diphenyl propane-1-one motifs in various naturally occurring biologically significant molecules inspired us to pursue the direct synthesis of these structural frameworks. Utilizing methanesulfonic acid (MeSO3H) as a catalyst, we achieved a more environmentally friendly and high-yielding synthesis, owing to its cost-effectiveness, biodegradability, transition-metal and additives free conditions. Furthermore, we have successfully extended our developed methodology to thiophenols, resulting in the production of sulfur-based butan-1-one derivatives in good yields. The presence of 1,4-diphenyl butan-1-one and 1,3-diphenyl propane-1-one motifs in various naturally occurring biologically significant molecules prompted us to develop a Br \& oslash;nsted acid-catalyzed Friedel-Crafts alkylation of phenols with Donor-Acceptor cyclopropane. image

}, keywords = {donor-acceptor cyclopropane, Friedel-Crafts alkylation, methanesulfonic acid, Phenols, thiophenol}, issn = {2193-5807}, doi = {10.1002/ajoc.202400116}, author = {Goswami, Lakshmi and Paul, Sayantan and Mamale, Ajay G. and Gonnade, Rajesh G. and Bhattacharya, Asish K.} } @article {49510, title = {Catalyst and transition-metal free 1,6-conjugate addition of azobisisobutyronitrile: access to isobutyronitrile containing diarylmethanes}, journal = {Organic \& Biomolecular Chemistry}, volume = {23}, year = {2025}, month = {APR}, pages = {3956-3966}, type = {Article}, abstract = {

A catalyst and transition-metal free 1,6-conjugate addition of azobisisobutyronitrile to para-quinone methides for the synthesis of isobutyronitrile containing diarylmethanes has been achieved. This protocol enables the synthesis of isobutyronitrile containing diarylmethanes in good yields and with a broad substrate scope. This is the first example wherein azobisisobutyronitrile has been used as a cyanide source for 1,6-conjugate addition under catalyst and metal-free conditions.

}, issn = {1477-0520}, doi = {10.1039/d5ob00012b}, author = {Mamale, Ajay G. and Ghodake, Balaji M. and Gonnade, Rajesh G. and Bhattacharya, Asish K.} }