19462-38-5Relevant academic research and scientific papers
Generation of phosphorus-centered radicals via homolytic substitution at sulfur
Carta, Paola,Puljic, Nicolas,Robert, Carine,Dhimane, Anne-Lise,Fensterbank, Louis,Lacote, Emmanuel,Malacria, Max
, p. 1061 - 1063 (2007/10/03)
(Chemical Equation Presented) A novel radical domino process relying on the homolytic cleavage of P-S bonds allows the preparation of phosphorus-containing molecules through addition of P-centered radicals onto olefins. The key step of this reaction is a homolytic substitution on a sulfur atom. The scope of the reaction is broad. Diaminophosphonyl radicals whose reactivity was unknown react smoothly with olefins. Use of tin hydride can be avoided. A radical thiophosphinoylation of triple bonds has been uncovered.
Organosilicon compounds with functional groups proximate to silicon. XVII. Synthetic and mechanistic aspects of the lithiation of α,β-epoxyalkylsilanes and related α-heterosubstituted epoxides
Eisch, John J.,Galle, James E.
, p. 293 - 314 (2007/10/02)
A series of α-heterosubstituted epoxides, , has been found to undergo lithiation in the temperature range of -75 to -115 deg C at the C-H bond of the epoxide.The substituent Z could be Me3Si, Ph3Si, n-Bu3Sn, Ph3Sn, PhSO2, (OEt)2PO and Ph; the groups R and R' were H, Ph and n-C6H13; and the lithiating reagents were n-butyllithium, t-butyllithium and lithium diisopropylamide in donor media of THF or TMEDA.The lithiation occurs with retention of configuration and the resulting lithio-epoxide is unstable above 0 deg C, decomposing in a carbenoid manner.The lithiation is facile except for compounds where Z and R (an alkyl or aryl) are cis-oriented; where Z = R3Sn, lithiation occurs by tin-lithium, rather than hydrogen-lithium, exchange.The lithio-epoxides thereby generated can be quenched with various reagents to yield epoxides where the epoxide H has been replaced by D, Me3Sn, R, RCO and COOH.The utility of this procedure in organic synthesis is emphasized.Finally, the possible explanations for the acidity of such α-heterosubstituted epoxides and for the relative stability of the derived lithio-epoxides are considered and assessed.
