“…The phosphorus(III) compounds, PR 1 R 2 R 3 , 1 (R 1 ס CF 3 , R 2 ס R 3 ס Me (1a) [12], iPr (1b) [13], NEt 2 (1c) [14]; R 1 ס NCO, R 2 ס R 3 ס OMe (1d), OEt (1e) [15], R 2 -R 3 ס OCH 2 CH 2 O (1f), OCMe 2 CMe 2 O (1g) [16]; R 1 ס OSiMe 3 , R 2 ס R 3 ס OEt (1h) [17]; R 1 ס NEt 2 , R 2 ס R 3 ס OCH 2 CF 3 (1i) [18]; R 1 ס R 2 ס Et 2 N, R 3 ס OCH 2 CF 3 (1j) [19], OCH(CF 3 ) 2 (1k) [20], OCH 2 Ph (1l) [21], OC 6 F 5 (1m) [19]) were reacted with 1,1,1,4,5,5,5-heptafluoro-4-(trifluoromethyl)-2,3-pentanedione (2) to yield 1,3,2k 5 r 5 -dioxaphospholenes 3a-m, mainly colorless liquids but solids in the case of 3f, 3g, and 3m (Scheme 1). There was no interaction of the isocyanato group in 1d-g with the diketone observed, unlike the corresponding reaction with hexafluoracetone [9][10][11] ( Table 1).…”