104012-59-1Relevant articles and documents
Catalytic Asymmetric Hydroalkenylation of Vinylarenes: Electronic Effects of Substrates and Chiral N-Heterocyclic Carbene Ligands
Ho, Chun-Yu,Chan, Chun-Wa,He, Lisi
supporting information, p. 4512 - 4516 (2015/04/14)
An asymmetric tail-to-tail cross-hydroalkenylation of vinylarenes with terminal olefins was achieved by catalysis with NiH complexes bearing chiral N-heterocyclic carbenes (NHCs). The reaction provides branched gem-disubstituted olefins with high enantioselectivity (up to 94% ee) and chemoselectivity (cross/homo product ratio: up to 99:1). Electronic effects of the substituents on the vinylarenes and on the N-aryl groups of the NHC ligands, but not a π,π-stacking mechanism, assist the steric effect and influence the outcome of the cross-hydroalkenylation.
A convenient and mild chromatography-free method for the purification of the products of Wittig and Appel reactions
Byrne, Peter A.,Rajendran, Kamalraj V.,Muldoon, Jimmy,Gilheany, Declan G.
supporting information; experimental part, p. 3531 - 3537 (2012/05/20)
A mild method for the facile removal of phosphine oxide from the crude products of Wittig and Appel reactions is described. Work-up with oxalyl chloride to generate insoluble chlorophosphonium salt (CPS) yields phosphorus-free products for a wide variety of these reactions. The CPS product can be further converted into phosphine.
Reactions of Cyclohexane Derivatives in Superacids
Dean, Christopher,Whittaker, David
, p. 1541 - 1543 (2007/10/02)
The reactions of menthol with FSO3H-SO2 and neomenthyl chloride with SbF5-SO2ClF follow different routes.The first yields a substituted cyclopentyl cation and the second a substituted cyclohexyl cation.Experiments on substituted cyclohexyl chlorides show that replacement of all the hydrogen atoms on the next but one carbon atom to the reaction centre blocks formation of a carbocation.It is suggested that ionisation of an equatorial chlorine atom takes place with assistance from an intramolecular electronic interaction, forming the methyl cyclopentyl carbocation in a synchronous process, rather than stepwise via the cyclohexyl carbocation.Reasons for contrasting behaviour in solvolytic reactions are discussed.
Chiral Picket Fence Porphyrins
Pfeiffer, Heinz-Peter,Sander, Hiltrud,Breitmaier, Eberhard
, p. 725 - 726 (2007/10/02)
The preparation of (+)-and (-)-meso-α,α,α,α-tetrakisphenyl>porphyrin as chiral picket fence porphyrins is described.The orientation of the p-menth-3-yl-carbonyl groups can be derived from proton NMR chemical shift data.Preparation procedures for the starting materials are described.
Menthyl-Substituted Phosphorus Compounds, II. L-Men(R)P(X)Cl (R = Cl, L-Me, D-Men; X = :, S). Characterization of Singular, Diastereotopic and Enantiotopic Menthyl Groups by 1H, 13C and 31P NMR Techniques
Haegele, Gerhard,Kueckelhaus, Wolfgang,Seega, Juergen,Tossing, Gudrun,Kessler, Horst,Schuck, Regina
, p. 1053 - 1063 (2007/10/02)
Menthyl-substituted phosphorus compounds L-Men(R)P(X)Cl (R = Cl, L-Men, D-Men; X = :, S) are synthesized. 1D and 2D NMR studies on nuclei 1H, 13C and 31P were used to characterize singular, diastereotopic and enantiotopic menthylgroups. - Key words: Menth
Models for the Ion-Pair Cluster Mechanism in Nucleophilic Substitution Reactions
Ramos, Socorro,Rosen, William
, p. 3530 - 3533 (2007/10/02)
Several bis(alkoxytriphenylphosphonium) salts have been prepared.When sterically constrained, as close neighbors, the leaving groups of these cations react rapidly at room temperature with negative nucleophiles to produce the expected substitution product.When sterically unconstrained, these types of functional groups behave as if they were mono(alkoxytriphenylphosphonium) salts, substituting very slowly or not at all at room temperature.The ion-pair cluster mechanism is discussed in light of these results.
