1,3,2λ⁵‐Benzothiazaphosphole 2‐Oxide and 1,3,2λ⁵‐benzoxazaphosphole 2‐oxide derivatives, new and versatile phosphorylating reagents

Abstract

The synthesis of the highly reactive five‐membered cyclic phosphorylating reagents 6a and 12 is described. The reagent 6a monophosphorylates alcohols without ring opening, whereas 12 diphosphorylates with ring opening yielding phosphate triesters.

1,3‐Chirality Transfer by Fragmentation of Allylsulfinic Acids: A Diastereoselective Approach to Vinyl Bromides Related to trans‐Hydrindane or trans‐Decalin

“…Rechromatography of the more polar fractions gave N ‐methyl‐2‐(2‐methylaminophenyldisulfanyl)aniline ( 20 ): 1 H NMR (200 MHz): δ = 2.78 (s, 3 H, CH 3 ), 2.80 (s, 3 H, CH 3 ) 4.8–5.0 (br., 2 H, N‐H), 6.46–6.64 (m, 4 H, aromatic‐H), 7.11–7.31 (m, 4 H, aromatic‐H) ppm. 13 C NMR (50 MHz): δ = 30.3, 109.7, 116.1, 118.4, 132.0, 137.0, 150.3 ppm, in agreement with data previously reported 21…”

“…After some experimentation it was found that sulfide 2a when treated first with BH 3 · THF (at –15 °C) and then, after the staring material had been consumed, with lithium aluminium hydride affords thiol 18a in 78 % yield after chromatography. Careful rechromatography of the more polar fractions gave another product: N ‐methyl‐2‐(2‐methylaminophenyldisulfanyl)aniline21 ( 20 ). Apparently, the primary benzothiazolyl moiety reduction product, 2‐(methylamino)benzenethiol, was oxidatively dimerized during the isolation procedure.…”

Phospholidines incorporating a β N-sulfonylaminoalcohol moiety: first observed selectivity of phosphorus heterocycle aminolysis in the presence of water

“…With water or alcohols we observed, as did Ugi et al, 12 that the phosphorylation leading to acids 9 or esters 10 is very fast. This is also the case with amines.…”

“…10 Consequently we turned to the use of preformed N-sulfonylamino-alcohols 2, 3 or -phenols 4 which are easily prepared, as described elsewhere. 11 Compounds 4 have in fact already been used by Ugi et al 12 for the synthesis of a few heterocycles 8, not for reactions with amines, but with alcohols (oligonucleotide synthesis). Several steps are then necessary due to the use of tricoordinated phosphorus compounds.…”

Controlling parameters for radical cation fragmentation reactions: Origin of the intrinsic barrier

“…2-Methylamino-benzenethiol was prepared according to a literature procedure by reductive ring opening of 2,3dihydro-1,3-benzothiazole (Aldrich) using lithium aluminum hydride (15). Methyl iodide, trimethyloxonium tetrafluoroborate, acetophenone, 1-phenyl-2-butanone, 1,1-diphenyl-acetone, cumene, α-methylstyrene, 1,1-diphenylethylene, and fluorene were all obtained from Aldrich Chemical Company and used without further purification.…”