A nanoscale iron catalyst for heterogeneous direct N- and C-alkylations of anilines and ketones using alcohols under hydrogen autotransfer conditions

Abstract

A heterogeneous and commercially available nanoscale iron catalyst for direct N- and C-alkylation reactions of anilines and methylketones with alcohols under hydrogen autotransfer conditions.

Zinc‐Catalyzed N‐Alkylation of Aromatic Amines with Alcohols: A Ligand‐Free Approach

“…The formation of 3 ad-d2 in the imine reduction process is probably attributed to the reversibility in the imine formation. [21] These results are consistent with the literature reports [21a-b] on D/H exchange, although the reduction of 4 ad with H 2 failed to yield the desired product under standard reaction conditions. Based on these studies, we believe that the present catalytic reaction proceeds via borrowing hydrogen or hydrogen autotransfer process [21] and not through carbocation intermediate.…”

“…[21] These results are consistent with the literature reports [21a-b] on D/H exchange, although the reduction of 4 ad with H 2 failed to yield the desired product under standard reaction conditions. Based on these studies, we believe that the present catalytic reaction proceeds via borrowing hydrogen or hydrogen autotransfer process [21] and not through carbocation intermediate. It also appears that zinc nitrate in the presence of potassium tert-butoxide oxidizes the benzyl alcohol and also reduces imine during the catalytic cycle.…”

“…Under standard reaction conditions, the reaction of isotopically enriched deuterated benzyl alcohol 1 a-d2 with 4-chloro aniline (2 d) afforded fully deuterated product 3 ad-d2 in 89.5% yield along with 3 ad-d1 in 10% (Scheme 7a). [21] The relative yields were determined by 1 H NMR spectroscopy. Besides, a reduction of imine 4 ad with 1 a-d2 was also investigated (Scheme 7b).…”

Phathalocyanine Metal Complexes (M=Fe, Co, and Cu) Catalyzed Aerobic Oxidation of 2-Amino-benzyl Alcohols to Access Quinazolines and Quinolines

“…Compared with aromatic nitriles, heterocyclic and aliphatic nitriles were less reactive. [19][20][21] Gratefully, for thiophene-2-carbonitrile (2m) and isonicotinonitrile (2n), quinazolines 3am and 3an could be obtained in 74% and 69% yields, respectively. Meanwhile, when the reaction was performed at 120 ℃ for 24 h, the aliphatic nitriles were also tolerated to provide 3ao～3as in 49%～74% yields.…”

“…Despite the above progress, for the synthesis of quinazoline with 2-aminobenzyl and benzonitrile alcohols, most of these methods require expensive catalysts, toxic reagents, excess oxidants, or harsh conditions, which limits their further applications [18,20] (Scheme 2). As for quinoline, the groups of Namitharan and Paul [21] have reported nano-Fe 2 O 3 -, Cu(II)-complex catalyzed syntheses of quinolines under longer time. On the basis of our experience in this area, [22] herein we developed MPcs (M＝Fe, Co and Cu) catalyzed doxidative coupling of 2-aminobenzyl alcohols with nitriles to access quinazolines under air.…”