Redox-neutral functionalization of α-Csp<sup>3</sup>–H bonds of secondary cyclic amines: a highly atom-economical strategy for <i>N</i>-arylation/formal cross-dehydrogenative couplings
作者:Priyankar Jha、Saddam Husen、Ravindra Kumar
DOI:10.1039/d0gc04258g
日期:——
An efficient redox-neutral method has been developed for α-Csp3–H functionalization of secondary cyclic amines via concurrent N-arylation/formal cross dehydrogenation coupling (CDC) with sp2-C–H and sp3-C–H bonds of arenes and ketones, respectively. The developed protocol is operationally simple, highly atom economical and environmentally benign (E-factor = ca. 0.5). The reaction mechanism has been
Quinone Alkylation Using Organocadmium Reagents: A General Synthesis of Quinols
作者:Aaron Aponick、Jason D. McKinley、Jeffrey C. Raber、Carl T. Wigal
DOI:10.1021/jo972300d
日期:1998.4.1
Reactions of p-benzoquinone with organocadmiumreagents yield quinols, the result of quinone carbonyl monoalkylation. The reactions proceed in good yield and are devoid of bisaddition and hydroquinone byproducts. Quinone alkylations using this method show general applicability to p-benzoquinone as well as extended quinone systems using primary alkyl, secondary alkyl, and aryl reagents.
A variety of substituted acridones were synthesized via a one-pot, metal-free cascade reaction. In this event, the DBU-mediated addition between quinols and ortho-methoxycarbonylaryl isocyanates formed a bicyclic oxazolidinone, followed by a sequence of intramolecular condensation, tautomerization, and decarboxylation, which led to the formation of acridones. The acridones showed mild activity against
A mild and efficient synthesis of bicyclic oxazolidinonesfrom quinols and isocyanates, under DBU-mediated conditions at room temperature, is described. The aza-Michael addition to substituted cyclohexadienones is stereoselective and chemoselective.
Regioselective and stereoselective cyclizations of cyclohexadienones tethered to active methylene groups
作者:Rodolfo Tello-Aburto、Kyle A. Kalstabakken、Kelly A. Volp、Andrew M. Harned
DOI:10.1039/c1ob06125a
日期:——
of 2,5-cyclohexadienones tethered to activated methylene groups was studied. The substitution around the cyclohexadienone ring serves to regioselectively direct these cyclizations based primarily on electronic effects. In the case of brominated substrates, these reactions proceed to give highly unusual electron-deficient tricyclic cyclopropanes. By using a Cinchona alkaloid-based phase-transfer catalyst