Synthesis of H‐Phosphinates by the UV Light–Mediated Fragmentation‐Related Phosphorylation Using Simple P‐Heterocycles
作者:Helga Szelke、János Kovács、György Keglevich
DOI:10.1080/00397910500297404
日期:2005.11
Photolysis of aryl-substituted 2,5-dihydrophosphole oxides (5a-e and 8) in the presence of methanol afforded methyl aryl-H-phosphinates (2a-e) in good yields. In the case of 1-ethyl-, cyclohexyl-, or ethoxy-2,5-dihydrophosphole oxides, the reaction was much slower (5f and 5h) or did not take place at all (5g). In such instances, the presence of an additional skeletal methyl group (7) or the use of the more strained 7-phosphanorbornene derivatives (6) promoted the fragmentation-related phosphorylations. Furthermore, the effect of the ring saturation in 8 and the possible extensions to 2-phosphabicyclo[3.1.0]hexanes (10a and 10f), a 1,2-dihydrophosphinine oxide (11), and a 1,2,3,4,5,6-hexahydrophosphinine oxide (12) were also investigated. Model compounds with P-phenyl substituent that are of sufficient ring strain (8, 10a, and 11) could be utilized well.