Regio- and stereospecific synthesis of allylic tertiary amines

Diphosphino-Functionalized MCM-41-Immobilized Rhodium Complex: A Highly Efficient and Recyclable Catalyst for the Hydrophosphinylation of Terminal Alkynes

“…As shown in Table 4, this heterogeneous rhodium complex-catalyzed hydrophosphinylation reaction can be readily applied to a variety of The binding energies are referenced to C 1s (284.6 eV), and the energy differences were determined with an accuracy of ±0.2 eV terminal alkynes, proving to be a practically useful method for the stereoselective synthesis of (E)-alkenylphosphine oxides which are not readily available by conventional methods. The hydrophosphinylation reaction of aliphatic terminal alkynes with HP(O)Ph 2 proceeded smoothly at 80°C to afford the corresponding (E)-adducts by the regioselective addition of the phosphorus atom at the terminal carbon of the triple bond in good to high yields (entries 1,2,8,9,11,12,17). The catalytic activity of this heterogeneous rhodium complex catalyst is comparable to that of homogeneous RhCl 3 .…”

“…In addition, a variety of heteroatom nucleophiles such as alcohols [7], thiols [8], primary and secondary amines [9][10][11], and phosphines [12] readily add to the double bond in alkenylphosphine oxides to afford versatile bifunctional compounds, which allow further synthetic transformations. Alkenylphosphine oxides have also been used for the formation of carbon-carbon bond via reactions with carbanion species [13] or carbon-centered radicals [14,15].…”

Synthesis of protected β,γ-unsaturated ketones from β-diphenylphosphinoyl ketones

“…One such anion, from ( 22 We have already reported the synthesis of P-diphenylphosphinoyl (Ph2PO) ketones ( 27) by three main methods (Scheme 9). We now report 22*23 that anions of the corresponding ketals (28) take part in Horner-Wittig reactions 24*25 in a regiospecific synthesis of P,y-unsaturated ketones (3 1). Some control over stereochemistry is also possible.…”

“…Some control over stereochemistry is also possible. (27) into the stable crystalline ketals (28) is routine-glycol, toluene-p-sulphonic acid (TsOH) in benzene or toluene under reflux-and gives good yields even with the most crowded ketones (Table 1). The only low yields in the Table are for conversion of alcohols (33) into ketals (28a) and (28g) by a three-step procedure: 21 ketones (27a) and (27g) are not intermediates.…”

“…The only low yields in the Table are for conversion of alcohols (33) into ketals (28a) and (28g) by a three-step procedure: 21 ketones (27a) and (27g) are not intermediates. In two other cases (Scheme 10) direct conversion of ketone precursors into ketals (28) gives higher yields than if ketones (28) are isolated. Thus the conditions for transposition of (34) to (27) can be made the same as those for ketal formation, giving 85% of (28f).…”