To the problem of the reaction mechanism of 2-methoxybenzo[d]-1,3,2-dioxaphosphorin-4-one with chloral on the basis of quantum-chemical calculations: II. The perkov reaction

Phosphonoxins III: Synthesis of α-Aminophosphonate Analogs of Antifungal Polyoxins with Anti-Giardia Activity

“…In the treatment of azide 16a with H 2 and Pd on BaSO 4 we propose the methyl phosphonate ester product 20 is consistent with a reactive intermediate involving the phosphonate moiety (Scheme ). Imine intermediates such as structure 27 have been proposed for catalytic hydrogenation of azides and oxaphosphiranes similar to proposed intermediate 28 have been described in other reaction pathways . Attack of methanol on such an intermediate should give heminaminal 29 , which after collapse to an α-ketophosphonate and stereoselective reduction would give the observed product 20 …”

Synthesis of Novel O,P,C-Cage Complexes via Thermal C−O Ring Opening of an Oxaphosphirane W(CO)5 Complex

“…The latter have been (mostly) claimed as reactive intermediates, and up to now only one stable derivative of III has been described; IV (E = lone pair) is still unknown. Theoretical calculations were recently performed on derivatives of IV (E = lone pair) and IV (E = two R groups) . In 1978, σ 4 λ 5 -oxaphosphiranes IV (E = NR) were synthesized via a [2+1] cycloaddition reaction of an iminophosphine derivative and hexafluoroacetone .…”

Protonation‐Induced Rearrangement of an Oxaphosphirane Complex

“…[1,2] Despite numerous experimental [3][4][5][6] and theoretical investigations, [7][8][9] oxiranium cations II have remained especially elusive proposed intermediates of acid-catalyzed ring-opening reactions. By comparison, protonation of s 3 l 3oxaphosphiranes [10][11][12][13][14] would presumably [15] yield P-protonated oxaphosphiranium species III, which are also unknown. In principle, kP metal coordination of a s 3 l 3 -oxaphosphirane complex should divert protonation to yield oxaphosphiranium complexes IV, and kinetic stabilization with a bulky substituent at phosphorus might allow observation of a closed-ring cation.Although oxaphosphirane complexes were first described by Mathey and co-workers almost 20 years ago, [16] and new synthetic methods, such as phosphinidene complex transfer to carbonyls [17,18] and reaction of phosphinidenoid complexes [19,20] with aldehydes, [19,21] have since been developed, the chemistry of oxaphosphiranes remains relatively undeveloped.…”

“…[1,2] Despite numerous experimental [3][4][5][6] and theoretical investigations, [7][8][9] oxiranium cations II have remained especially elusive proposed intermediates of acid-catalyzed ring-opening reactions. By comparison, protonation of s 3 l 3oxaphosphiranes [10][11][12][13][14] would presumably [15] yield P-protonated oxaphosphiranium species III, which are also unknown. In principle, kP metal coordination of a s 3 l 3 -oxaphosphirane complex should divert protonation to yield oxaphosphiranium complexes IV, and kinetic stabilization with a bulky substituent at phosphorus might allow observation of a closed-ring cation.…”