Alkenylphosphine oxides

NMR monitoring of the reaction of the palladium complex with 1-octyne suggested that the alkyne inserts into the Pd-H bond. Further heating produced a mixture of the two regioisomeric alkenylphosphine oxides, the anti-Markovnikov adduct being the favored product (54 46, 65% yield). 

The alkenylphosphine oxide Ph2P(0)H reacts with [Pt(PEt)3] at room temperature to give cis-[PtH(P(0)Ph2)(P(0H)Ph2)(PEt3)] (9), the crystal structure of which reveals a novel intramolecular hydrogen bond.65... 

Polyphosphoric acid (PPA) (115%) has been used in a very convenient preparation of phosphindoline 1-oxides and phosphinoline 1-oxides by cyclization of various alkenylphosphine oxides (12).14 Isophosphindole oxide (13) has been pre-... 

Lithiated ( )- and (Z)-2-alkenylphosphine oxides and phosphonates react with cyclic enones in a 1,4-conjugate addition manner (Schemes 19 and 20). The ( )- and (Z)-allylic anions react in highly dia-stereoselective fashion to deliver respectively syn and anti vinylic phosphine oxides and phosphonates. Chiral allylphosphonyl anions undergo enantioselective 1,4-addition with cyclic enones of varying... 

Dipole Moments. - The polarity and conformation in solution of 2-thiophosphoryl-l,3-dithianes (100) has been studied by the dipole moment method and using IR spectral data. In solution, they exist mainly as an equilibrium of two chair-like conformers with axial orientation of the phosphorus-containing substituent. The polarity and conformations of alkenylphosphine oxides (115) and related acetates (116) have also been determined. ... 

Another interesting catalytic transformation involving alkynes is the hydro phosphinylation, which affords alkenylphosphine oxides [62]. The formation of hydride-phosphinito compounds is one of the key steps of the reaction. These species are formed by oxidative addition of the P-H bond of diphenylphosphine oxide to platinum(O) and palladium(O) complexes, which act as catalytic precursors. In this context, it should be mentioned that a novel method to prepare hydride-phosphinito compounds has been recently reported. The new strategy starts from 133 and involves the oxidative addition of the P-H bond of... 

Noble metals like Pd and Rh are not always required a Cul/ethylenediamine catalyst precursor promoted regioselective addition of diphenylphosphine oxide to terminal alkynes to yield -alkenylphosphine oxides (Scheme 8) [16]. When... 

Hydrophosphinylation of 1-octyne with diphenylphosphine oxide (105) afforded the alkenylphosphine oxide 106 by internal attack with high regioselectivity. However, addition of a small amount of Ph2P(0)OH changed the regioselectivity to provide the product 107 by terminal attack [32]. 

AlkenyIphosphonium salts and alkenylphosphine oxides are both of use in the synthesis of carbocyclic and heterocyclic systems, and new routes to these derivatives are of value. Cycloalkenes react... 

A rhodium-catalyzed hydrophosphinylation was developed to give the corresponding alkenylphosphine oxide (eq 42). ... 

The oxidative decarbojylative coupling of alkenyl acids with diphenylphosphine oxide in the presence of Ni(dppf)Cl2 and Ag20 furnished ( )-l-alkenylphosphine oxides (Scheme 27). ... 

For the Rh catalyst the catalytic cycle was reported to involve alkyne insertion into the metal-hydrogen bond (Scheme 8.31). Thus, this reaction is a suitable synthetic route for the preparation of E-alkenylphosphine oxides. In contrast,... 

Niu M, Fu H, Jiang Y, Zhao Y (2007) Copper-catalyzed addition of H-phosphine oxides to alkynes forming alkenylphosphine oxides. Chem Commun 272—274... 

These organocopper intermediates were successfully trapped with electrophiles such as allyl bromide, acyl chlorides, and diphenylchlorophosphine, but not with benzaldehyde and methyl iodide. The resulting products were subjected to in situ oxidation with elemental sulfur to form stable alkenylphosphine sulfides 353 [103]. Owing to its synthetic potential, the regioselective carbometallation of substituted ynol ethers has recentiy witnessed a renaissance [91aj. Thus, the alkynyl ethers 354 were treated under different carbocupration conditions (Scheme 10.121). 

Han L-B, Zhao C-Q, Onozawa S-y, Goto M, Tanaka M. Retention of configuration on the oxidative addition of P—H bond to platinum(O) complexes the first straightforward synthesis of enantiomerically pure P-chiral alkenylphosphinates via palladium-catalyzed stereospecific hydrophosphinylation of alkynes. J. Am. Chem. Soc. 2002 124 3842-3843. 

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