Achille Umani-Ronchi

Catalytic asymmetric Friedel-Crafts alkylations

GENERAL ASPECTS AND HISTORICAL BACKGROUND Introduction General Aspects and Historical Background Catalytic Enantioselective FC Reactions: An Introduction MICHAEL ADDITION Chelating Alpha, Beta-Unsaturated Compounds Simple Alpha, Beta-Unsaturated Substrates Nitroalkenes ADDITION TO CARBONYL COMPOUNDS Aldehydes/Ketones Imines NUCLEOPHILIC ALLYLIC ALKYLATION AND HYDROARYLATION OF ALLENES Introduction Allylic Alkylations Metallo-Catalyzed Hydroarylation of Allenes NUCLEOPHILIC SUBSTITUTION ON CSP3 CARBON ATOMS Ring-Opening of Epoxides Direct Activation of Alcohols UNACTIVATED ALKENES Introduction Early Studies Rh(I)-Catalyzed Enantioselective Hydroarylation of Iminoarenes Pt(II)-Catalyzed Enantioselective Hydroarylation of Alkenylidoles Au(II)-Catalyzed Enantioselective Hydroarylation of Allenylindoles Conclusions and Outlook Experimental: Selected Procedures CATALYTIC ASYMMETRIC FRIEDEL-CRAFTS ALKYLATIONS IN TOTAL SYNTHESIS Introduction Total Synthesis of Indole-Containing Compounds Total Synthesis of Pyrrole-Containing Compounds Friedel-Crafts Alkylation of Furan Derivatives in Total Synthesis Friedel-Crafts Alkylation of Arenes in Total Synthesis Asymmetric Synthesis of Natural Products Based on Diastereoselective Friedel-Crafts Reactions INDUSTRIAL FRIEDEL-CRAFTS IN CHEMISTRY Introduction Green Chemistry and the Friedel-Crafts Reaction Heterogeneous Catalysts for the Friedel-Crafts Reaction Large Scale Hydrocarbon Processing Conclusions and Perspectives

The First Catalytic Enantioselective Nozaki–Hiyama Reaction

The Nozaki-Hiyama reaction can be performed in an enantioselective catalytic way! The catalytic system utilizes 10 mol % of an inexpensive chiral [Cr(salen)] complex. The [Cr(salen)]/Mn/Me(3)SiCl system effectively promotes the enantioselective addition of allyl chloride to aliphatic and aromatic aldehydes at room temperature (65-89 % ee, 40-60 % yield).

Catalytic enantioselective conjugate addition of indoles to simple α, β-unsaturated ketones

Chiral [Al(salen)Cl] complex (10 mol%) in the presence of 2,6-lutidine (10 mol%) was found to be effective in catalysing the enantioselective Friedel–Crafts-type conjugate addition of indoles (3) to (E)-arylcrotyl ketones (2), furnishing the corresponding β-indolyl ketones in excellent yield and high enantioselectivity (ee up to 89%).

Catalytic asymmetric synthesis promoted by a chiral zirconate: Highly enantioselective allylation of aldehydes

Abstract A new chiral Lewis acid catalyst, [BINOL-Zr(O i Pr) 2 ], is prepared from ( R ) or ( S )-BINOL and commercially available Zr(O i Pr) 4 · i PrOH; it efficently promotes the enantioselective allylation of aldehydes by allyltributyltin in shorter times and at lower temperatures with respect to related catalysts.

Indium tribromide: a highly effective catalyst for the addition of trimethylsilyl cyanide to α-hetero-substituted ketones

Abstract The catalytic addition of trimethylsilyl cyanide (TMSCN) to a large variety of hetero-substituted ketones promoted by anhydrous InBr3 has been studied. The low catalytic loading (0.1–1 mol%) and the mild experimental conditions required represent the key features of this novel catalytic system.

Electrochemiluminescent functionalizable cyclometalated thiophene-based iridium(III) complexes.

A family of new functional bis-cyclometalated thiophene-based cationic iridium complexes have been prepared and fully characterized. The introduction of formyl groups into the thienyl-based cyclometalating ligand (thpy-CHO) allows one to perform further functionalizability and to confer to the whole species potentially interesting perspectives as functional materials. The X-ray crystal structures of three complexes, namely, [Ir(thpy)(2)bpy]PF(6), [Ir(thpy-CHO)(2)bpy]PF(6), and [Ir(thpy-CHO)(2)phen]PF(6), are reported. A rich reduction voltammetric pattern of the complexes is outlined, and the effect of the substituents on the cyclic voltammetric behavior is fully elucidated. Finally, the electrochemiluminescence spectra of all of the species have been obtained in acetonitrile by annihilation of the one-electron-oxidized and -reduced forms, showing very similar features with respect to the luminescence (as both the shape and energy of the emission bands).

Catalytic asymmetric syntheses of secondary alcohols using cis-1-amino-2-indanols as chiral ligands

Abstract Both enantiomers of cis-1-amino-2-indanols (1a,b) have been used as chiral ligands in the catalytic asymmetric reduction of ketones with BH3·SMe2 affording secondary alcohols with enantiomeric excesses up to 95%. Furthermore, some N,N-diakyl derivatives of 1a,b catalyzed the enantioselective addition of diethylzinc to aldehydes.

The first catalytic enantioselective Nozaki–Hiyama–Kishi reaction

Abstract Herein we report the first example of a catalytic enantioselective Nozaki–Hiyama–Kishi reaction performed with a catalytic amount of chiral chromium complex. A large variety of non-stereogenic and stereogenic reactive halides can be added to aldehydes to afford the corresponding alcohols with excellent stereoselectivity using a catalytic amount of chiral chromium complex

Highly diastereoselective pinacol coupling of aldehydes catalyzed by titanium-Schiff base complexes

Abstract A new effective methodology for a highly diastereoselective pinacol coupling of aldehydes is described. The method employes 3 mol % of a complex prepared in situ from TiCl 4 (THF) 2 and a Schiff base in acetonitrile. The catalytic cycle is realized with Me 3 SiCl and Mn as reducing agent. The dependence of the diastereoselectivity on the Schiff base used is reported.

Enantioselective addition of Et2Zn to aldehydes promoted by a chiral Schiff base metal complex

Abstract An optically active zinc complex prepared with ligand 1 has been used to promote the enantioselective addition of Et 2 Zn to aldehydes. This study represents a new application for these metallo-salen complexes.