107407-83-0Relevant academic research and scientific papers
New Method for the Classification of Nucleophiles in the Palladium-Catalyzed Substitution of Allylic Acetates
Fiaud, Jean-Claude,Legros, Jean-Yves
, p. 1907 - 1911 (1987)
Palladium-catalyzed reactions of nucleophiles were carried out on cyclopent-2-enyl acetate (1), 3a,4,5,6,7,7a-hexahydro-(1α,3aα,4α,7α,7aα)-4,7-methano-1H-inden-1-yl acetate (3b), and 3a,4,5,6,7,7a-hexahydro-(1β,3aα,4α,7α,7aα)-4,7-methano-1H-inden-1-yl acetate (5b) to give indications on the mechanism of the reaction and the mode of attack of the nucleophiles.The lack of reactivity of 3b confirmed that a trans relationship between the approaching Pd(O) complex and the departing acetate is required in the η3-allyl-forming step.Examination of the reactivity of the nucleophiles with 5b compared to 1 allowed a decision as to whether the primary attack of the intermediate (η3-allyl)palladium complex by the nucleophile is directed to η3-allylic ligand (Nu1 nucleophiles: sodium dimethyl malonate, sodium cyclopentadienide, lithium thioxodiphenylphosphide, morpholide) or to the metal (Nu2 nucleophiles: phenylzinc chloride, sodium indenide, ammonium formate).
Enantio- and Diastereoselective Suzuki–Miyaura Coupling with Racemic Bicycles
Goetzke, F. Wieland,Mortimore, Mike,Fletcher, Stephen P.
, p. 12128 - 12132 (2019/08/02)
Herein, we describe a rhodium-catalyzed enantio- and diastereoselective Suzuki–Miyaura cross-coupling between racemic fused bicyclic allylic chlorides and boronic acids. The highly stereoselective transformation allows for the coupling of aryl, heteroaryl
Stereochemistry of the palladium-catalyzed allylic substitution: The synanti dichotomy in the formation of (π-allyl)palladium complexes and their equilibration
Stary, Ivo,Zajicek, Jaroslav,Kocovsky, Pavel
, p. 7229 - 7250 (2007/10/02)
The mechanism of palladium(0)-catalyzed allylic substitution has been investigated with the aim of finding whether or not the intermediate (π-alryl)palladium complexes can arise in a syn fashion as an alternative to the well known anti-mechanism. Using (diphenylphosphino)acetate as a leaving group and stereochemically biased substrates 30b and 35b evidence for the syn stereochemistry has been acquired (30b → 31 and 35b → 36). This reversal of stereochemistry is facilitated by severe steric congestion in the starting allylic esters (which impairs the ordinary anti-mechanism) and is boosted by the pre-coordination of the Pd(0) reagent to the leaving group. The latter effect apparently lowers the activation entropy. With cyclohexene derivatives 10b, 18b, and 19b and acyclic substrate 25b, where steric hindrance does not operate, the anti-mechanism producing η3-complexes dominates even for (diphenylphosphino)acetates. At elevated temperature, rapid equilibration of η3-complexes (13 ? 14 and 20 ? 21) has been observed prior to the reaction with a nucleophile. This effect has been attributed to the presence of (diphenylphosphino)acetate ion acting as a ligand for palladium.
