97125-56-9Relevant academic research and scientific papers
Fixation of heterocumulenes, II. - A study on the reaction of lithiated allyl systems with CO2, isocyanates and isothiocyanates
Piffl, Michaela,Weston, Jennie,Anders, Ernst
, p. 2851 - 2859 (2007/10/03)
The regioselectivity of the reaction of 1-(thiophenyl)- (Li-6), 1-(phenylsulfinyl)- (Li-12), 1-(phenylsulfonyl)- (Li-15) and 1-(diethoxyphosphoryl)allyllithium (Li-18) with CO2, PhNCO and PhNCS is investigated. Carboxylation of the allyl sulfide 6 and the allyl sulfoxide 12 proceeds with low regioselectivity. On the other hand, an exclusive γ-selectivity is achieved for reactions of CO2 with Li-15 and Li-18. Both carboxylations are reversible and can be directed to give a-products by using low temperature workup (0 °C). In contrast to CO2, PhNCO reacts with the allylic compounds investigated here to give amides with a high degree of regioselectivity: α-Attack is found for the sulfide 6 and the sulfone 15 whereas the reaction occurs at the γ-terminus for the sulfoxide 12 and the phosphonate 18. Exclusive α-attack is observed for all sulfur-substituted allyllithium compounds on reaction with PhNCS. In contrast to this, reaction of the phosphonate 18 with PhNCS yields exclusively the γ-product.
Reactions of α-or χ-Phenylthio Substituted Extended Enolate Anions Derived from Esters
Brownbridge, Peter,Durman, John,Hunt, Paul G.,Warren, Stuart
, p. 1947 - 1958 (2007/10/02)
The title anions are alkylated and acylated (α series only) exclusively at the α position.The α-phenylthio products give χ-phenylthio compounds by the PhS shift and the PhS group may be removed from the products in a number of ways.
