33493-32-2Relevant articles and documents
Geminal difunctionalization of α-diazo arylmethylphosphonates: Synthesis of fluorinated phosphonates
Zhou, Yujing,Zhang, Yan,Wang, Jianbo
, p. 10444 - 10453 (2016/11/18)
A general approach towards diverse fluorinated phosphonates via geminal difunctionalization reactions of α-diazo arylmethylphosphonates is described. The diazo functionality (RR′CN2) is successfully converted to RR′CF2, RR′CHF, RR′CFBr or RR′CFNR′′2 groups by employing different fluorination reagents. A variety of fluorinated organophosphorus compounds were readily accessed in good to excellent yields from a common type of precursor.
Asymmetrie hydrogenation of α,ss-unsaturated esterphosphonates
Huang, Yange,Berthiol, Florian,Stegink, Bart,Pollard, Michael M.,Minnaard, Adriaan J.
experimental part, p. 1423 - 1430 (2009/12/24)
The rhodium-catalyzed asymmetric hydrogenation of readily available α,ss-unsaturated esterphosphonates affords the corresponding α-chiral phosphonates in excellent yield and ee. The resulting products are useful multifunctional building blocks applied in
α-OXYIMINOPHOSPHONATES: CHEMICAL AND PHYSICAL PROPERTIES. REACTIONS, THEORETICAL CALCULATIONS, AND X-RAY CRYSTAL STRUCTURES OF (E) AND (Z)-DIMETHYL α-HYDROXYIMINOBENZYLPHOSPHONATES
Breuer,Eli,Karaman, Rafik,Goldblum, Amiram,Gibson, Dan,Leader, Haim,et. al.
, p. 3047 - 3058 (2007/10/02)
Dialkyl α-oxyiminoalkylphosphonates, obtained by treatment of dialkyl acylphosphonates with hydroxylamine or methoxylamine, are mostly mixtures of E and Z isomers.Structural assignments of the oximes were based on X-ray crystallographic analysis of representative compounds: (E)- and (Z)-dimethyl α-hydroxyiminobenzylphosphonates .The (31)P n.m.r. chemical shifts of the E isomers always appear at lower field than those of the corresponding Z isomers.Thermal fragmentation of (1a) affords benzonitrile and dimethyl hydrogen phosphate, with (Z)-(1a) reacting faster than the E isomer. α-Oxyiminophosphonates undergo EZ isomerisation catalysed either by acid or by base under certain conditions, the E isomer being the thermodinamically more stable one.An E + Z mixture of dialkyl α-oxyiminophosphonates can be mono-de-alkylated by non-basic nucleophiles (e.g.NaI) to afford monoalkyl oxyiminophosphonates of unchanged isomeric composition.The geometrical isomers of α-hydroxyiminophosphonates differ in their behaviour under basic conditions.While treatment of (E)-(1a) with NaOH in boiling methanol leads, by mono-de-alkylation, to sodium methyl α-hydroxyiminobenzylphosphonate , under the same conditions (Z)-(1a) undergoes fragmentation, by C-P bond cleavage, to benzonitrile and dimethyl hydrogen phosphate.Control experiments established that the fragmentation of (Z)-α-hydroxyiminophosphonates involves an intramolecular attack on the phosphorous atom by the ionized Z oriented oxime oxygen.Similar differences in behaviour are noted between the isomers of the monoanions of α-hydroxyiminophosphonates.MNDO/H Calculations demonstrate the feasibility of forming internal hydrogen bonds in Z isomers, and their possible contribution to conformational preferences.Single-crystal X-ray diffraction studies of (E)- and (Z)-(1a), and (E)-(2b), clearly identified the geometric isomers and correlated them with (1H) and (31)P n.m.r. resonances.
