Hydroxymethylation of quinolines via iron promoted oxidative C–H functionalization: synthesis of arsindoline-A and its derivatives

Abstract

Herein, we report a mild and efficient hydroxymethylation of quinolines via an iron promoted cross-dehydrogenative coupling reaction under external acid free conditions.

Synthesis of Substituted Pyrano[3,4‐b]Quinolines by Silver‐Catalyzed Regioselective Intramolecular Cyclization of 3‐Alkynylquinoline Aldehydes

“…In continuation of our efforts towards the synthesis of 3‐alkynylquinoline aldehydes, herein we have choosen 4‐aryl‐3‐alkynylquinoline ( 4 a ‐ l) as a model substrate and treated with excess amount of methanol which acts as both reagent as well as solvent in presence of Fe(ClO 4 ) 2. x 6H 2 O and H 2 O 2 as an oxidant at room temperature in 10 min. The desired product (4‐aryl‐3‐alkynylquinolin‐2‐yl)methanol ( 5 a – l ) obtained up to 61–75% yields [26] . Thus, hydroxymethylated quinolines were well tolerated with different functional groups, with alkyne group in 3‐position remain unaffected.…”

“…The desired product (4-aryl-3alkynylquinolin-2-yl)methanol (5 a-l) obtained up to 61-75% yields. [26] Thus, hydroxymethylated quinolines were well tolerated with different functional groups, with alkyne group in 3position remain unaffected. These alcohols were further transformed into respective aldehydes with the help of Dess-Martin as an oxidant, to generate the derivatives of 4-aryl-3-alkynylquinoline-2-carbaldehydes (6 a-l) (Scheme 2).…”

“…Our group has been actively involved in exploring the transition metal catalyzed oxidative cross dehydrogenative coupling reactions, for the synthesis of N‐heterocyclic compounds [25] . Recently, we have disclosed Fe‐catalyzed hydroxymethylation of quinolines via methanol as a C 1 source [26] and these hydroxylmethylated quinolines were further transformed into respective aldehydes. Later, we have explored nucleophilic addition of primary arylamines with ortho‐alkynyl cyclopropanes, to the synthesis of 1,2‐dihydroisoquinoline malonates by using Ni(II) and Cu/Ag catalyts [27] .…”

Discovery of antibacterial agents targeting biofilm formation: total synthesis and in vitro investigation of amycolasporins

“…17,18 The reduction of compound 10 generated the resultant alcohol (97% yield), which was oxidized into 4-pyridine-carboxaldehyde 7 in 92% yield with Dess-Martin periodinane (DMP). [19][20][21] With intermediate 7 in hand, the next goal was the preparation of intermediate 5b (Scheme 2). Treatment of intermediate 7 with trimethylsilyl cyanide (TMSCN) in the presence of zinc iodide (ZnI 2 ) and then hydrolysis with HCl (2 N) provided α-hydroxy-4-pyridineacetonitrile 6 in 87% yield over 2 steps.…”

“…By following the procedure of method A, compound 20 and compound 11 were synthesized using compound 7 (3. 20 (21). By following the procedure of preparing compound 18, the title compound was synthesized using compound 20 (2.00 g, 10.22 mmol) and Grubbs' 1 st generation catalyst (421 mg, 0.51 mmol) in anhydrous CH 2 Cl 2 (200 mL).…”