One-pot tandem 1,4–1,2-addition of phosphites to quinolines

Abstract

Trialkyl and silylated dialkyl phosphites were evaluated as phosphorus nucleophiles for the addition to quinolines in a strong acidic medium allowing consecutive 1,4- and 1,2-addition breaking up the aromatic stabilisation, thereby leading to 2,4-diphosphono-1,2,3,4-tetrahydroquinolines in one single reaction step in moderate to good yields (2-84%).

Triazole‐Based Anion‐Binding Catalysis for the Enantioselective Dearomatization of N‐Heteroarenes with Phosphorus Nucleophiles

“…[8,9] However,besides few examples of the racemic addition of phosphites to the N-acyl salts, [10] mosto ft he common metal-free routes to a-amino phosphonic acids from heteroarenes requireh arsh temperatures and acidic conditions, hamperingt he development of selective and asymmetric versions. [11] In this regard,t he Mukherjee group recently reported on at hiourea-based anion-binding-catalyzed [12,13] asymmetric dearomatization of isoquinolines by acylation and subsequent reactionw ith trimethylsilyl-substituted phosphites (Scheme1, middle). [14] Inspired by this work and based on the observed superior performance of our recently developedt riazole-based chiral H-donor catalyst [15] with the more challengingq uinolines and pyridines, [16,17] we decided to explore the enantioselective dearomatization of theseh eteroarenes with phosphorus nucleophiles (Scheme 1, bottom).…”

Recent Advances in the Construction of Phosphorus‐Substituted Heterocycles, 2009–2019

“…In 2010, the Stevens group elaborated a one‐pot tandem 1,4–1,2‐addition of dialkyl H ‐phosphites to quinoline derivatives, which provided various 2,4‐diphosphono‐1,2,3,4‐tetrahydroquinolines 216 in moderate to good yields with 36:64 to 1:99 dr . In the presence of 50 mol% of H 2 SO 4 , the phosphonation with DMPTMS (dimethyl trimethylsilyl phosphite) worked well in spite of the loss of aromatic stabilization (Scheme ).…”

Pd-catalyzed carbonylative access to aroyl phosphonates from (hetero)aryl bromides

“…As this new carbonylative transformation only requires a slight excess of CO generated from 1.5 equivalents of COgen, the 45 methodology is adaptable to isotope labelling. 14 Simply applying 13 COgen instead of COgen, allowed products [ 13 C]-3a and [ 13 C]-3e to be prepared in good yields after subjection to the optimised reaction conditions (Scheme 3). 17 Having established a mild and efficient Pd-catalysed 50 carbonylative strategy for the synthesis of aroylphosphonates, we set out to underline the utility of these products (Scheme 4).…”

“…19 Scheme 3. 13 C-Labelling of aroylphosphonates using 13 COgen. Hydrazine also proved reactive towards 3g, producing the hydrazone derivative 6 in good yield.…”