Chiral ferrocene ligands have been widely used in asymmetric catalysis. The advantages of using as a scaffold for chiral are described, particularly those regarding planar chirality, rigid bulkiness, and ease derivatization. role chirality 1,2- 1,1'-disubstituted systems is discussed. By bulky fragment, novel were designed, high enantioselectivity regioselectivity achieved the allylic substitution reaction monosubstituted allyl substrates. Using tunable electronic properties...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTHighly Regio- and Enantioselective Pd-Catalyzed Allylic Alkylation Amination of Monosubstituted Acetates with Novel Ferrocene P,N-LigandsShu-Li You, Xia-Zhen Zhu, Yu-Mei Luo, Xue-Long Hou, Li-Xin DaiView Author Information State Key Laboratory Organometallic Chemistry Shanghai Institute Organic Chinese Academy Sciences, 354 Fenglin Lu 200032, China Cite this: J. Am. Chem. Soc. 2001, 123, 30, 7471–7472Publication Date (Web):July 10,...

Electronic properties of the ligands switch diastereoselectivity in Cu-catalyzed 1,3-dipolar cycloaddition azomethine ylides to nitroalkenes: exo- or endo-pyrrolidines were obtained with high diastereo- and enantioselectivities presence different chiral (phosphanylferrocenyl)oxazoline (e.g. 3 a, b).

Tuning of diastereoselectivity was realized in the Mannich reaction glycine derivatives with aromatic and aliphatic N-Ts imines using CuClO4−FcPHOX ligand 4b 4f having an MeO group at 4-position F atom 3,5-position phenyl ring on P-atom respectively as catalyst, providing either anti- or syn-α,β-diamino acid high yields diastereo- enantioselectivities.

Pd-catalyzed asymmetric allylic alkylation reactions of acyclic ketones with monosubstituted allyl substrates using 1,1'-P,N-ferrocene H as substituent on the oxazoline ring ligand gave products having two chiral centers high yields and regio-, diastereo-, enantioselectivities, ratio branched linear being 98:2, anti:syn for 7−21:1, ee anti-products 92−99%.

Acylsilanes as a new type of "hard" carbon prenucleophile reacted with monosubstituted allyl reagents under Pd-catalyzed asymmetric allylic alkylation reaction conditions to provide products high regio-, diastereo-, and enantioselectivities. The usefulness the protocol has been demonstrated by ready conversion allylated into corresponding alcohols, esters, ketones retention stereochemistry well enantioselective synthesis cis-3-ethyl-4-phenylpiperidine cinnamomumolide.

Abstract A palladium‐catalyzed asymmetric [3+2] cycloaddition reaction of vinylaziridines with α,β‐unsaturated ketones, wherein the alkenes have a single activator, is realized in high diastereo‐ and enantioselectivity, thus affording 3,4‐disubstituted pyrrolidines yields excellent ee values. The introduction methyl group at C1 vinyl greatly improves stereochemistry reaction. plausible transition state proposed.

Tributylphosphine was found to be an effective promoting reagent for the ring-opening reaction of various epoxides and aziridines with nucleophile produce corresponding anti-bifunctional products in moderate excellent yields water.

[figure: see text] Ferrocene-modified chiral pocket ligands have been studied in the palladium-catalyzed asymmetric alkylation of simple ketone enolates, which (R,R,Sp,Sp)-1 containing two pairs matched chiralities, central chirality and planar chirality, behaved very efficiently this reaction up to 95% ee value was achieved.

Ring-opening reactions of aziridines with trimethylsilyl compounds triggered by tetrabutylammonium fluoride give the corresponding products regioselectively in excellent yield. It provides a facile and efficient procedure for ring-opening affords practical access to synthesis cyano-, azido-, or chloroamines because its efficiency simplicity. The are easily transformed vicinal diamines beta-amino acids.

Pocket the difference: Highly enantioselective allylic alkylation of simple acyclic ketones is carried out by using a Pd catalyst with "chiral pocket" ligand 1 (see scheme). The addition Lewis acid such as AgBr and selection one enolate form over another dramatically affect enantioselectivity reaction. Supporting information for this article available on WWW under http://www.wiley-vch.de/contents/jc_2002/2005/z502020_s.pdf or from author. Please note: publisher not responsible content...

Even acyclic amides are suitable nucleophile subtrates for asymmetric allylic alkylations. The allylation products formed in high yields the presence of a palladium catalyst with 1,1′-P,N ferrocene ligand (see scheme; R=(S)-1,1′-bi-2-naphthol). nature substituents on nitrogen atom amide has critical effect efficiency and selectivity reaction. Supporting information this article is available WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z704629_s.pdf or from author. Please note:...

Steric interactions of the substituents weaken strong NH … N hydrogen bonds (typical for porphycenes) in 1 (R = Me, Et) by increasing distance. As a consequence coordination metal ions, particular Zn2+ is facilitated. These findings can be expected to give impetus research into metalloporphycenes.

A series of benzylic substituted P,N-ligands 1 and 2 have been synthesized. The Pd-complexes these ligands show high catalytic activity enantioselectivity in catalyzing the asymmetric Heck reaction. dramatic switch is realized using with without substituents at position ligand. Ligands H as offer products (R)-configuration while methyl result (S)-configuration products. In most cases enantioselectivities are achieved. Density functional theory calculations on reaction mechanism well X-ray...

The shining: Readily accessible BINOL amino alcohol (S)-1 is a highly enantioselective fluorescent sensor for structurally diverse α-hydroxycarboxylic acids, and the first recognition of linear aliphatic acids α-tertiary-hydroxycarboxylic acids.

A fine selection: The installation of chiral centers at the α position ketones is achieved with excellent enantioselectivity by means iridium-catalyzed asymmetric hydrogenation α,β-unsaturated under mild conditions. catalyst incorporates a phosphinooxazoline (PHOX)-based ligand, which exhibits high levels induction (see scheme; BArF−=tetrakis[3,5-bis(trifluoromethyl)phenyl]borate; cod=cyclooctadiene). Detailed facts importance to specialist readers are published as "Supporting Information"....

The kinetic resolution of a carbon nucleophile is realized for the first time via Pd-catalyzed asymmetric allylic alkylation with "unstabilized" ketone enolates as nucleophile, providing both allylated 2,3-disubstituted 2,3-dihydro-4-quinolones and recovered substrates in high yields ee (S-factor 40-145). application methodology organic synthesis demonstrated by ready transformation an adduct into pyrrolo[3,2-c]quinoline, which features core structure biologically active Martinella alkaloids.

A highly diastereo- and enantioselective cyclopropanation reaction was realized in the of acyclic amides with monosubstituted allyl carbonates via Pd-catalysis using a ferrocene ligand H as substituent on an oxazoline ring, providing cyclopropane products having three chiral centers yields 67−83%, dr ratio being 4−23:1, ee 83−97%. The presence LiCl is important for gain high enantioselectivities reaction.

α-Carbanions of cyclic and acyclic imines have been successfully applied as nucleophiles in the Pd-catalyzed allylic alkylation reaction. Tuning chemo- regioselectivity has realized by using t-BuOK/THF LDA/toluene to give branched linear products, respectively, with high regio- diastereoselectivities. A plausible mechanism is proposed on basis experimental results DFT calculations.

The palladium-catalysed allylic substitution reaction is one of the most important reactions in transition-metal catalysis and has been well-studied past decades. Most proceed through an outer-sphere mechanism, affording linear products when monosubstituted allyl reagents are used. Here, we report efficient Palladium-catalysed protocol for β-substituted ketones with substrates, simply by using N-heterocyclic carbene as ligand, leading to branched up three contiguous stereocentres a (syn,...

Diastereo- and enantioselective cycloaddition of 3-nitroindoles with vinyl aziridine was realized under Pd-catalysis using commercially available Walphos as the ligand, affording pyrroloindolines in high yields diastereo- enantioselectivities. The reaction can be scaled up to a gram scale products are easily converted amino pyrroloindoline other derivatives.

An asymmetric [3 + 2] cycloaddition reaction of vinyl epoxides with α,β-unsaturated ketones, the single activated electron-deficient alkenes, has been achieved under Pd-catalysis in excellent diastereo- and enantioselectivity. The utilities protocol are demonstrated by transformation products into other useful chiral molecules. Density functional theory calculations rationalize stereocontrol reaction.