P‐Substituted 3‐phosphabicyclo [3.1.0] hexane 3‐oxides from diastereoselective substitution at phosphorus

Abstract

Preparation of P-am ino-3-phosphabicy

Synthesis of achiral and new chiral crown ethers containing a triphenylphosphane unit

“…We note here that in the MS spectra of the phosphanes 1, (R,R)-2, (S,S)-3 and (S,S)-4 only the molecular peaks for the appropriate phosphanones could be found. The completion of the phosphanone-phosphane transformation was proved by 31 P-NMR (the difference of the concerning δ values was larger than 45), IR (the lack of the peaks for phosphanones in the spectra of phosphanes) and TLC analysis (big differences in R f values).…”

“…13 C-NMR spectra were taken either on a Bruker DRX-500 Avance spectrometer (125.8 MHz, reference: TMS) or on a Brucker 300 Avance spectrometer (75.5 MHz, reference: TMS) and it is indicated in each individual case. 31 P-NMR spectra were recorded on a Brucker 300 Avance spectrometer (121.5 MHz, reference: H 3 PO 4 ). HPLC-DAD-MS/MS experiments were performed on an Agilent 1200 HPLC system(G1379B degasser, G1312B binary gradient pump, G1367C autosampler, G1316B column thermostat and G1315C diode array detector) coupled with an Agilent 6410 triple quadrupole mass spectrometer equipped with an ESI ion source (Agilent Technologies, Waldbronn, Germany).…”

Cyclic Phosphinates by the Alkylation of a Thermally Unstable 1-Hydroxy-1,2- Dihydrophosphinine 1-Oxide and A 3-Hydroxy-3-Phosphabicyclo[3.1.0]Hexane 3-Oxide

“…7 The alkylations were carried out using two equivalents of the alkyl halide in the presence of K 2 CO 3 as the base and, occasionally, triethylbenzylammonium chloride (TEBAC) as the catalyst, in acetone, or acetonitrile. The alkylations were accomplished by stirring at room temperature, at reflux, or by MW irradiation.…”

“…3,5 Another possibility for the preparation of new species is the modification of the functionality of phosphorus in the heterocycle. [7][8][9] A novel approach is the conversion of a phosphinic acid to the phosphinate by direct esterification. This is impossible under thermal conditions, but it was found to take place on microwave (MW) irradiation at around 200 • C in a sealed reaction vessel (Scheme 1a).…”

Alkylating esterification of 1‐hydroxy‐3‐phospholene oxides under solventless MW conditions

“…The method is also applicable for the synthesis of cyclic phosphinates, such as 1-alkoxyphospholene 1-oxides (3) involving the hydroxyphospholene oxide (2) as the starting material and the chlorophospholene oxide (4) as the intermediate (Scheme 1) [3,4]. The alkoxyphospholene oxides (3) can also be obtained directly by the alcoholysis of the phospholium salts (1) [5][6][7] available from the McCormack cycloaddition of a variety of dienes with phosphorus tribromide. According to a recent method developed by the Keglevich group, the hydroxyphospholene oxides can be directly esterified by alcohols under solventless MW conditions [8].…”