Synthesis and fragmentation of new 2‐phosphabicyclo[2.2.2]octene 2‐oxides

Fragmentation‐related phosphinylations using 2‐aryl‐2‐phosphabicyclo[2.2.2]oct‐ 5‐ene‐ and ‐octa‐5,7‐diene 2‐oxides

“…The purity of the phosphinic derivatives (7-13) characterized by 31 P and, in some cases, by 13 C NMR spectroscopical data was ca. 95% according to GC-MS.…”

“…The starting aryl-dihydro-1H-phosphole oxides (1a and 1b), the phosphabicyclohexanes (2a-1, 2b-1, and 2b-2), and the double-bond isomers (A and B) of the dihydrophosphinine oxides (3a and 3b) were characterized by 31 P, 13 C, and 1 H NMR, as well as mass spectroscopical data. The spectral parameters showed close resemblance to those of earlier described analogues [15][16][17].…”

“…3:2 isomeric mixture after column chromatography (Scheme 2). The isomers (A and B) of the products (4a and 4b) were characterized by 31 P, 13 C, and 1 H NMR, as well as mass spectroscopical data.…”

“…Another way of utilizing the phosphabicyclooctene derivatives in phosphinylations is their UV light-mediated reaction with alcohols or amines [6][7][8][9][10]. Besides the eliminationaddition (EA) mechanism via a methylenephosphine oxide, a novel addition-elimination (AE) route involving an intermediate with a pentavalent pentacoordinated phosphorus atom was also substantiated by us [9,10,12,13].…”

2-Ethyl-2-phosphabicyclo[2.2.2]oct-7-ene derivatives: Synthesis and use in fragmentation-related phosphorylations

“…The fragmentation-related phosphorylations are of interest, as they require mild reaction conditions, especially those accomplished under photochemical conditions, (26 • C and an irradiation of only several hours) and take place efficiently and in a selective way [5,6,8]. During our efforts to find suitable precursors and to evaluate the mechanism of the fragmentations, a series of novel phosphabicyclooctene derivatives were described [9][10][11]. To extend the sphere of the precursors available, bridged P-heterocycles with ethyl substituent on the phosphorus atom are introduced and their fragmentation properties are described in the present paper.…”