Phosphine carbonyl adducts

Nucleophilic Attack at Other Atoms. A highly efficient general synthesis of secondary- and tertiary- phosphine-borane adducts is afforded by treatment of the phosphine with sodium borohydride in the presence of acetic acid in THF. Any carbonyl groups present in the phosphine undergo concomitant... 

The carbonyl adducts of allyl phosphine oxides, e. g., 24 and 29 can also be used to make allyl alcohols32 by the reductive removal of the Ph2PO group with lithium aluminium hydride a reaction involving transposition of the double bond, e. g., 24 36. In this approach, the allyl anion of 23 is a reagent for the vinyl anion synthon 37. 

The Morita-Baylis-Hillman or Baylis-Hillman reaction involves the reaction between an electrophile 1, usually a carbonyl containing compound such as an aldehyde, ketone, or imine, and an activated alkene 2 in the presence of a catalyst such as an amine or phosphine to deliver an a-methylene- 3-hydroxy carbonyl or a-methylene-p-amino carbonyl adduct 3. 

The application of 3-aminopropyl phosphine (3) [41,46] as a building block for incorporation into -COOH functionalized frameworks provides an excellent example of the utility of preformed primary phosphine frameworks (Scheme 8) [46]. The reactions involved Michael addition of ferf-butyl acrylate to malonic acid dimethyl ester to produce the intermediate adduct, 2-methoxycarbonyl-pentanedioc acid 5-ferf-butyl ester 1-methyl ester, which upon treatment with trifluro-acetic acid (TFA) produced the corresponding diester acid,2-methoxy-carbonyl-pentanedioic acid 1-methyl ester, in near quantitative yield. It is remarkable to note that the reaction of NH2(CH2)3PH2 (3) with the diester acid is highly selective as the -COOH group remained unattacked whereas the reaction occurred smoothly and selectively at the -COOMe groups to pro-... 

Wickman and Silverthom [276] have investigated bond properties in molecular adducts of the planar Vaska type compound frans-h s(triphenyl-phosphine)iridium carbonyl chloride, IrCl(CO) ((C6H5)3P)2, with small molecules such as H2, O2, CI2, I2, CH3I, and HCl. They essentially observed a decrease of the isomer shift in the following series of adduct molecules XY H2 > HCl > CH3J > O2 > I2 > CI2,... 

Carbanions derived from phosphine oxides also add to carbonyl compounds. The adducts are stable but undergo elimination to form alkene on heating with a base such as sodium hydride. This reaction is known as the Horner-Wittig reaction.268... 

Zig-zag chains are also obtained starting from many other neutral tectons wherein the donor and/or acceptor sites have an angled geometry, e.g. (Z)-diazaalkenes [171]2, phosphine oxides [79], carbonyl [150], phosphoramidyl [124,139], and sulfinyl [151] sites, tetrahedral molecules that work as bidentate modules (e.g. the adducts CBr4/DABCO [172],... 

Materials. The commercially available aldehydes were distilled prior to use and stored at 0°C under argon. The cyclohexene- and cyclopentene- aldehydes, and the indane aldehyde (see Table) were gifts from Professor E. Piers of this department. The Ru(TPP)(PPh3)2 complex (1) was prepared from Ru(TPP)(CO)(EtOH) and PPh3 (1,7), while Ru(TPP)(CO)(tBu2POH), was prepared from the carbonyl (ethanol) adduct by treatment with tBu2PCl (1). The phosphines were from Strem Chemicals, and the ruthenium was obtained as RuCl Ol O from Johnson, Matthey Limited. 

Ru3(CO)10(Ph2C2)2, and Ru3(CO)9(C2(Ph)2)3 (128). The dinuclear complex Ru2(CO)6(C2Ph2)2, containing a metallocyclopentadiene ring similar to that observed for both iron and osmium, is a further product in the reaction this does imply very similar structures for the trinuclear adducts to those observed for iron and osmium. The carbonyl reacts with tetracyclone to yield the complex Ru3(CO)i0(C2Ph2)2, which may be related to the osmium compounds discussed later. Phosphine substitution of the carbonyls in some of these compounds has been established. 

NR = nonreactive toward hydrocarbons PO = oxidation of phosphines to phosphine oxides MF — peroxometallacyclic adduct formation with cyanoalkenes NSE — nonstereoselective epoxidation SE=stereoselective epoxidation AE = asymmetric epoxidation HA- hydroxylation of alkanes HB=hydroxylation of arenes OA = oxidation of alcohols to carbonyl compounds K = ketonization of Lermina 1 alkenes SO oxidation of S02 to coordinated S04 MO = metallaozonide formation with carbonyl compounds I = oxidation of isocyanides to isocyanates. 

The normal reaction of tertiary phosphines is to replace metal-coordinated carbonyl groups (Section III,E,1) or, less commonly, to form adducts with P—>Si bonds (Section III,D). In special cases, however, cleavage of the Si-metal bond may occur directly (entries 63, 66, 66a, and 67) the manganese derivative is discussed further in Section... 

---