Iodine-Catalyzed Efficient Hydrophosphonylation of N-Tosyl Aldimines

Abstract

Treatment of N-tosyl aldimines with dialkyl trimethylsilyl phosphites at 0 degrees C in the presence of iodine as a catalyst afforded the corresponding sulfonamide phosphonates in excellent yields within 1.5 to 2.5 h.

Hydrophosphonylation of Aldimines under Catalysts‐Free Conditions

“…Dimethyl (4-methylphenylsulfonamido) (phenyl) methyl phosphonate (3a) [ Dimethyl (4-methylphenyl) (4-methylphenylsulfonamido) methyl phosphonate (3b) [5] White solid, 110 mg (95%); m.p. 187-189 ; Dimethyl (4-methoxyphenyl) (4-methylphenylsulfonamido) methyl phosphonate (3c) [5] White solid, 103 mg (86%); m.p. 160-161 ; Dimethyl (4-chlorophenyl) (4-methylphenylsulfonamido) methyl phosphonate (3e) [5] White solid, 99 mg (82%); m.p.…”

“…In contrast to dialkyl phosphites, an alternative strategy through nucleophilic addition of readily available trialkylsilyl phosphite to suitable electrophiles was farless examined. [4] Recently, the group of Das [5] used trialkylsilyl phosphites as nucleophilic reagents successfully in iodine molecular catalyzed aminophosphonylation of N-tosyl aldimines, obtained sulfonamide phosphonates in excellent yields. And more recently, we discovered that N-heterocyclic carbenes (NHCs) [6] can also promote the Pudovik reaction of trimethylsilyl phosphite with aldehydes efficiently, giving α-hydroxyphosphonates in good yields.…”

HIO3/KI: A new combination reagent for iodination of aromatic amines and trimethylsilylation of alcohols and phenols through in situ generation of iodine under mild conditions

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Although molecular iodine is a versatile catalyst in organic synthesis, it is highly corrosive, toxic and sublimable, making its use somewhat unattractive and also there are some environmental hazards with respect to its handling. In order to overcome these disadvantages with molecular iodine, an attempt to introduce molecular iodine in situ in the reaction mixture seems to be practically useful.…”

Simple, Efficient, and Catalyst‐Free Synthesis of (2‐Amino‐4H‐1‐benzopyran‐4‐yl)phosphonates in Polyethylene Glycol

“…-In continuation of our work [4] on the development of useful synthetic methodologies, we observed that the multicomponent reaction of salicylaldehydes (¼ 2-hydroxybenzaldehydes) 1, malononitrile or ethyl cyanoacetate 2, and trialkyl phosphites 3 in polyethylene glycol (PEG) at 808 produced the corresponding (2-amino-4H-1-benzopyran-4-yl)phosphonate derivatives 4 (Scheme).…”