Kohsuke Aikawa

The axial chirality of tropos gold–biphep (biphep=bis(phosphanyl)biphenyl) complexes, which is controlled by a chiral anion such as (S)-2 (=X*−), is imprinted and memorized even after the dissociation of chiral anion. An enantiopure complex thus obtained efficiently function as an atropos asymmetric catalyst in an intramolecular hydroamination. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or ty

The aromatic perfluoroalkylation catalyzed by a copper(I) salt with bis(perfluoroalkyl)zinc reagents Zn(RF)2(DMPU)2, which were prepared and then isolated as a stable white powder from perfluoroalkyl iodide and diethylzinc, was accomplished to provide the perfluoroalkylated products in good-to-excellent yields. The advantages of this reliable and practical catalytic reaction are 1) air-stable and easy-to-handle bis(perfluoroalkyl)zinc reagents can be utilized, 2) the reagent is reactive and henc

The trifluoromethylation of carbonyl compounds is accomplished by the stable (trifluoromethyl)zinc reagent generated and then isolated from CF3I and ZnEt2, which can be utilized as a trifluoromethyl anion source (CF3(-)). The reaction proceeds smoothly with diamine as a ligand and ammonium salt as an initiator, providing the corresponding trifluoromethylated alcohol products. Moreover, the (trifluoromethyl)zinc reagent can also be employed as a difluorocarbene source (:CF2) not only for gem-difl

The palladium-catalyzed Negishi cross-coupling reaction of aryl iodides and bromides with (difluoromethyl)zinc reagent bearing a diamine such as TMEDA is achieved to provide the difluoromethylated aromatic compounds in good to excellent yields. The advantages of (difluoromethyl)zinc reagent are that (1) the derivatives, which possess different stability and reactivity, can be readily prepared via ligand screening and (2) transmetalation of a difluoromethyl group from the zinc reagent to palladiu

Abstract A synergistic effect is observed for the combination of a neutral dinuclear gold complex with a chiral silver phosphate in the intramolecular hyroalkoxylation of allenes to give furan derivatives in high yields and enantioselectivities. The monocationic dinuclear gold complex affords higher catalytic activity and enantioselectivity than the neutral or dicationic digold complexes. The synergistic effect is thus highly promising to provide a guiding principle in designing an efficient chi

A highly enantioselective and atom-economical [2 + 2] cycloaddition of various alkynes with trifluoropyruvate using a dicationic (S)-BINAP-Pd catalyst has been established. This is the first enantioselective synthesis of stable oxetene derivatives, whose structure has been clarified by X-ray analysis. This catalytic process offers a practical synthetic method for oxetene derivatives (catalyst loading: up to 0.1 mol %), which can serve as novel chiral building blocks for pharmaceuticals and agroc

A highly enantioselective alkynylation catalyzed by the dicationic (S)-BINAP−Pd complex with a variety of alkynylsilanes and trifluoropyruvate is described. The catalytic reaction is applicable to highly enantioselective addition of polyyne to trifluoropyruvate to construct α-trifluoromethyl-substituted tertiary alcohols as enantiomerically enriched forms. The alkynyl products can be converted into a chiral allene bearing a trifluoromethyl group.

High enantioselective [4 + 2] cycloaddition can be achieved by cationic Rh complexes bearing not only chiral phosphine but also chiral diene. This is the first example of asymmetric synergy between chiral dienes and diphosphines.

A highly stereoselective catalytic alkylation sequence for the synthesis of highly functionalized and versatile five-membered-ring compounds bearing all-carbon quaternary stereocenters was developed. Enantioselective desymmetrization of achiral cyclopentene-1,3-diones was thus executed by chiral Cu-phosphoramidite catalysts. A variety of complicated cyclopentane derivatives can be synthesized with excellent stereoselectivities using a low catalyst loading in a one-pot operation.

Die axiale Chiralität der abgebildeten Gold-Biphep-Komplexe wird durch ein chirales Anion wie (S)-2 (=X*−) vorgegeben und bleibt auch nach der Abspaltung dieses Anions bestehen. Ein auf diese Weise erhaltener enantiomerenreiner Komplex katalysierte eine asymmetrische intramolekulare Hydroaminierung. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by

Chiral dicationic palladium complex-catalyzed vinylation and dienylation of glyoxylate with vinylsilanes and dienylsilanes to produce highly optical active allylic alcohols has been achieved. The advantages of this reaction are that the chiral palladium catalyst is readily employed and that vinylsilanes as nucleophiles are easily synthesized, storable, and air- and moisture-stable.

All enantiopure atropisomeric (atropos) ligands essentially require enantiomeric resolution or synthetic transformation from a chiral pool. In sharp contrast, the use of tropos (chirally flexible) ligands, which are highly modular, versatile, and easy to synthesize without enantiomeric resolution, has recently been the topic of much interest in asymmetric catalysis. Racemic catalysts bearing tropos ligands can be applied to asymmetric catalysis through enantiomeric discrimination by the addition

Abstract Chiral dicationic Pd‐complex‐catalyzed enantioselective ene and aldol reactions with various isatin derivatives are shown to produce the corresponding 3‐hydroxy‐2‐oxindole products in good yields with high enantioselectivities. These catalytic processes are effective not only with isatins but also with keto esters and diketones derivatives. Even with unprotected isatin, high yields and enantioselectivities were obtained to produce convolutamydine A as a naturally occurring compound. Seq