Herein we report an organocatalytic synthesis of highly fluorescent naphthalene derivatives through hydrogen atom transfer featuring neat and mild reaction conditions under air with high substrate tolerance along with atom economy by the unprecedented use of DBU, where oxidation and reduction occurred in one‐pot. Synthesized compounds are utilized in photophysical studies, cytotoxic studies and cell imaging studies of colon cancer cell line CT26.
Herein, the reversal of polarity of cationic bromine, organocatalytically, is presented. NBS, a proven bromocation source was converted to a superior bromoanion reagent by H/Br exchange with a secondary amine, substantiated with spectroscopic and computational evidences. The concept has further been used in a successful accelerated organocatalyzed dibromination of olefins, in a non-hazardous, commercially viable process with a wide substrate scope. The reactivity of key entities has been observed through NMR kinetics and reaction acceleration using 10 mol% of catalyst loading accounts for its major success. The nucleophilicity of the bromoanion was found to be superior in comparison to other nucleophiles such as MeOH, H2O etc. and the protocol dominates over competing allylic bromination reaction.
Herein a successful chemoselective either functionalization of the nucleophilic sites of prolinol by exploiting the relative acidity difference and inverted nucleophilicity of the corresponding conjugate bases, employing a suitable base is reported. An elaborate investigation into the overlooked sensitivity of reaction conditions to a highly utilized protocol has been reported. As an example, mono-Boc functionalization of prolinol for the exclusive synthesis of either NBoc/OBoc/Oxazolidinone derivatives is reported. Failing to emulate the former protocols, a mechanistic investigation was initiated which revealed that the rudimentary steps can be controlled by: a) a requisite base to recognize the differently acidic sites (NH and OH) for the formation of the conjugate base reacting to the electrophile, b) the disparity in nucleophilicity of the completely formed conjugate basic sites. This protocol has been extended to be successful with various other substrates, which might prove to be applicable as suitable catalysts in asymmetric reactions. Never-reported-before substrates such as O-Boc, O-CBz, O-Bz and O-ethyl carbonate derivatives of prolinol were synthesized in good to excellent yields along with other substrates.
Herein, organocatalytically achieved polarity reversal of cationic bromine is presented. The proven bromocation source N‐bromosuccinimide (NBS) was converted to a superior bromoanion reagent by H/Br exchange with a secondary amine, substantiated with spectroscopic and computational evidence. The concept has further been used in a successfully accelerated organocatalyzed dibromination of olefins in a non‐hazardous, commercially viable process with a wide range of substrate scope. The reactivity of key entities observed through NMR kinetics and reaction acceleration using only 10 mol % of catalyst account for its major success. The nucleophilicity of the bromoanion was found to be superior in comparison to other nucleophiles such as MeOH and H2O also the protocol dominates over the competing allylic bromination reaction.
An
investigation into the sensitivity of reaction conditions to
a highly utilized protocol has been reported, wherein the mono-Boc
functionalization of prolinol could be controlled for the exclusive
synthesis of either N-Boc, O-Boc,
or oxazolidinone derivatives. Mechanistic investigation revealed that
the elementary steps could possibly be controlled by (a) a requisite
base to recognize the differently acidic sites (NH and OH) for the
formation of the conjugate base, which reacts with the electrophile,
and (b) the difference in nucleophilicity of the conjugate basic sites.
Herein, a successful chemoselective functionalization of the nucleophilic
sites of prolinol by employing a suitable base is reported. This has
been achieved by exploiting the relative acidity difference of NH
and OH along with the reversed nucleophilicity of the corresponding
conjugate bases N– and O–. This
protocol has also been used for the synthesis of several O-functionalized prolinol derived organocatalysts, few of which have
been newly reported.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.