Chiral monodentate phosphine ligands for the enantioselective α- and γ-arylation of aldehydes
作者:Ivan Franzoni、Laure Guénée、Clément Mazet
DOI:10.1016/j.tet.2014.02.079
日期:2014.7
phosphine ligands elaborated on the binepine scaffold is described. Their application in the Pd-catalyzedintramolecularasymmetricα-arylation of aldehydes and the intermolecular asymmetric γ-arylation of α,β-unsaturated aldehydes provides a mean of validating the design of these ligands. For the first reaction, excellent reactivities have been obtained while only modest enantioselectivities were measured
A general Pd-catalyzed α- and γ-benzylation of aldehydes for the formation of quaternary centers
作者:Ivan Franzoni、Laure Guénée、Clément Mazet
DOI:10.1039/c5ob00702j
日期:——
A palladium-catalyzed benzylation of α-branched aldehydes has been developed using benzyl methyl carbonates. The method gives access to congested quaternary centers in the vicinity of one of the most sensitive carbonyl functionalities and displays unprecedented generality with respect to both coupling partners. Evidence for the direct involvement of a Pd-η3-benzyl intermediate is provided. Extension
the enaminones 4a–4e by the following two routes: (A): Acylation of the enamines, 2, derived from 1 and secondary amines (pyrrolidine, morpholine and piperidine) by ethyl chloroformate, and (B): Condensation of 1 with diethyl oxalate, giving the β-ketoesters 3, followed by reaction with the secondary amines. Ethyl 2(-1-pyrrolidinyl)-1-cyclopentene-1-carboxylate, 4f, and methyl 3-(1-pyrrolidinyl)-2-butenoate
Veilchenriechstoffe. 26. Mitteilung. Synthese des 1,1,7-Trimethyl-3-(buten-31-ylon-33)-cyclohepten-(2), eines 7-gliedrigen Analogons des ?-Irons
作者:L. Ruzicka、C. F. Seidel、H. Schinz、M. Pfeiffer??
DOI:10.1002/hlca.19480310219
日期:——
In dieser Srbcit ist die Synthese eines 7-gliedrigen Analogons des,βIrons (vgl. Formel XXVIII) beschrieben. Die Synthese dieser Verbindung, sowie auch eines Isomeren derselben, mit umgelagertem Kohlenstoffgerüst, wurde vor mehreren Jahren durchgeführt, als für das Iron noch eine Konstitutionsfwmel mit einem 7-gliedrigen Ring angenommen wurde.
Silicon-DirectedNazarov Reactions II. Preparation and Cyclization of ?-Silyl-substituted Divinyl Ketones
作者:Todd K. Jones、Scott E. Denmark
DOI:10.1002/hlca.19830660802
日期:1983.12.14
Two general methods for the preparation of β-silyl-substituted divinyl ketones have been developed starting from either α, β-unsaturated aldehydes or simple ketones. Anhydrous FeCl3 induces the cyclization to cyclopentenones under mild conditions and in good yields with predictable and complete control over the position of the double bond in the five-membered ring. The observed effects of substituents