L. Ronzini

Iron catalyzed cross-coupling reactions of acyl chlorides with Grignard reagents. A mild, general, and convenient synthesis of aliphatic and aromatic ketones

Abstract Acyl chlorides couple with Grignard reagents at room temperature in the presence of catalytic amounts of tris(acetylacetonate)iron(III), Fe(acac) 3 . The reaction is general with respect to both reactants and provides a very mild and convenient method for the synthesis of aliphatic and aromatic ketones.

A highly efficient synthetic route to ketones through sequential coupling reactions of Grignard reagents with S-phenyl carbonochloridothioate in the presence of nickel or iron catalysts

Abstract The sequential coupling reactions of Grignard reagents with S phenyl carbonochloridothioate in the presence of nickel(II) or iron(III) catalysts provides a very mild and straightforward route to symmetrical and unsymmetrical aliphatic and aromatic ketones.

Functionalized ketones by iron mediated reaction of grignard reagents with acyl chlorides

Abstract The iron(III)-catalyzed cross-coupling reaction between Grignard reagents and acyl chlorides was found to be widely applicable to the synthesis of various functionalized ketones in good yields under mild conditions; the series of examples includes the synthesis of chiral methyl ketones and symmetric diketones.

Stereospecific synthesis of (1E,3Z)- and (1E,3E)-1-trimethylsilyl-1,3- dienes by means of sequential cross-coupling reactions

Abstract A new synthesis of stereodefined 1-trimethyl-1,3-dienes is described. The method is based on two sequential coupling reactions between Grignard and the readily available (Z)- or (E)-1-bromo-2-phenyl-thioethene, in the presence of transition metal catalysts.

One-step synthesis of ketones from car☐ylic acids and grignard reagents in the presence of a nickel(II)-phosphine catalyst.

Abstract A one-step synthesis of diaryl and alkyl-aryl ketones by the reaction of car☐ylic acid with Grignard reagents in the presence of NiCl2(Ph2PCH2CH2PPh2) as catalyst is described. In the nickel-catalyzed Grignard reaction the formation of alcohols is nearly completely suppressed.

Stereospecific synthesis of alkenyl sulphides by cross-coupling reactions of secondary alkyl Grignard reagents with Z- or E-1-bromo-2-phenylthioethene in the presence of transition metal catalysts

Abstract Z - and E -1-bromo-2-phenylthioethenes were cross-coupled stereospecifically with s-alkyl Grignard reagents in the presence of a series of Ni II , Pd II or Fe III catalysts with the aim of finding a catalyst which would not cause s-alkyl → n-alkyl isomerization. With PdCl 2 (dppf) (dppf = 1,1′-bis(diphenylphosphino)ferrocene) and NiCl 2 (dppe) (dppe = 1,2-bis(diphenylphosphino)ethane) there was still some isomerization contribution, but it was completely suppressed by using iron(III) catalysts.

An easy route to insect pheromones with a E-Z or Z-E conjugated diene structure

Abstract Insect pheromones having a conjugated diene system of E-Z or Z-E configuration can be prepared with high stereoselectivity, by means of addition reactions of Z -dialkenyl cuprates to phenylthioacetylene. The alkadienyl sulphides intermediates are then subjected to a cross-coupling reaction with Grignard reagents, in the presence of a Ni(II) complex as a catalyst, leading to the desired pheromones.

Synthesis of α-amino acid derivatives by copper(I)-catalyzed conjugate addition of grignard reagents to methyl 2-acetamidoacrylate

Abstract The reactions of Grignard reagents with methyl 2-acetamidoacrylate in the presence of CuI give fair to good yields of α-amino esters; the corresponding α-deutero- or α-methyl-derivatives are obtained upon quenching with D + or CH 3 I, respectively.

Asymmetric selection via elimination. A novel route to partially resolved sulphoxides

Elimination reactions between β-halogenoethyl aryl sulphoxides and optically active bases provide a useful route to partically resolved sulphoxides whose configuration is dependent upon the nature of the chiral reagent and of the leaving group.

A general approach to the synthesis of mono-olefinic insect sex pheromones of Z- or E-configuration.

A series of insect sex pheromones and structurally related olefins have been synthesized with high stereoisomeric purity by two sequential cross-coupling reactions. Starting with (Z)- or (E)-1-bromo-2-phenylthioethene, (1) and (2), and Grignard reagents in the presence of nickel or palladium catalysts, two types of compounds have been prepared: (i) 1,2-dialkylethenes and (ii) alkenyl acetates. In the synthesis of the Z-isomers, the first step involves a cross-coupling reaction of compound (1) with the appropriate Grignard reagent in the presence of a catalytic amount of [PdCl2(PPh3)2]. The second cross-coupling reaction is performed on the intermediate (Z)-phenylthioalkenes using a different Grignard reagent in the presence of [NiCl2(dppe)](dppe = Ph2PCH2CH2PPh2) as a catalyst. In the synthesis of E-isomers both steps are cross-coupling reactions of Grignard reagents in the presence of [NiCl2(dppe)] as a catalyst, the first step involving compound (2) and the second step involving the intermediate (E)-phenylthioalkenes obtained. The Grignard reagents used in the synthesis of the alkenyl acetates derive from protected ω-halohydrins.