Cu-catalyzed oxidative Povarov reactions between N-alkyl N-methylanilines and saturated oxa- and thiacycles

Abstract

Cu-catalyzed oxidative Povarov reactions between N,N-dialkylanilines and saturated oxa- or thiacycles with tert-butyl hydroperoxide (TBHP) are described; notably, the reactions use neither [4π] nor [2π]-motifs as the initial reagents. The use of cheap alkane-based substances as building units is of mechanistic and practical interest as two inert sp(3) C-H bonds are activated.

Practical synthetic strategies towards lipophilic 6-iodotetrahydroquinolines and -dihydroquinolines

“…However, the desired product 6 can be isolated using basic alumina chromatography. Reductive amination with acetone, mediated by AcOH and NaOAc was also pursued as an alternative strategy [18]. While being much easier to purify due to the elimination of the bis-alkylation product, the yield of this approach was much more variable at larger scales.…”

Visible light-mediated C P bond formation reactions

“…In 2018, Lei and co-workers [32] realized the breakthrough of oxidative C(sp 3 )AH phosphonylation of N,Ndialkylaniline derivatives by synergistically combining visible light-induced photoredox catalysis with proton-reduction catalysis (Scheme 2). Note that, this process is performed under external oxidant free conditions and the oxidative breakage of CAN bond side reactions can be successfully avoided [33,34]. Under optimal reaction condition, a variety of N-alkyl substituted anilines, such as N,N-dialkylanilines, cyclic amines can be phosphonylated in good to high yields.…”

Construction of N‐Heterocycles through Cyclization of Tertiary Amines

“…Liu and co-workersm ade significant progress on the development of oxidative Povarov reactions (Scheme 2). [14] In this new approach, they found that the double oxidationoft ertiary amines 4 and tetrahydrofuran derivatives 5 was feasible under the same catalysis system. In the presence of ac atalytic amount of Cu powder or Cu(OTf) 2 ,t he cycloaddition reactions between N-methyl anilinesa nd saturated oxa-or thiacycles, such as tetrahydrofuran, tetrahydrothiophene, tetrahydro-2Hpyran, and tetrahydro-2H-thiopyran, proceeded smoothly to afford ad iversearray of N-heterocycles 6.…”

“…Liu and co‐workers made significant progress on the development of oxidative Povarov reactions (Scheme ) . In this new approach, they found that the double oxidation of tertiary amines 4 and tetrahydrofuran derivatives 5 was feasible under the same catalysis system.…”