A catalyst system composed of Pd(OCOCF3)2 complexed with the electron-donating, rigid chiral diphosphane TangPhos gives excellent enantioselectivities (up to 99 % ee) and conversions >99 %) in hydrogenation N-tosylimines 1 (see scheme). variety aromatic, aliphatic, cyclic amines 2 can be prepared by this methodology. Supporting Information for article is available on WWW under http://www.wiley-vch.de/contents/jc_2002/2006/z600263_s.pdf or from author. Please note: The publisher not...

A Rh(III)-catalyzed annulation between salicylaldehydes and diazo compounds with controllable chemoselectivity is described. AgNTf2 favored benzofurans via a tandem C–H activation/decarbonylation/annulation process, while AcOH led to chromones through activation/annulation pathway. The reaction exhibited good functional group tolerance scalability. Moreover, only single regioisomer of benzofuran was obtained due the in situ decarbonylation orientation effect.

A 1,6‐addition arylation reaction of para ‐quinone methides with α‐isocyanoacetamides and electron‐rich aromatic compounds under metal‐free conditions has been developed. BF 3 · Et 2 O plays two roles in the reaction: catalyzing cyclization to give oxazoles, activating achieve process. The shows good functional group tolerance, scalability, regioselectivity. It is a consice protocol for synthesis diverse unsymmetrical triarylmethanes. Further transformation resulting triarylmethanes provides...

Diaryl ethers are important structural motifs widely found in bioactive natural products, ligands, and catalysts. While there a variety of methods available to generate diaryl ethers, progress on the construction axially chiral has been slow. We report herein an atroposelective copper-catalyzed cycloaddition between bisalkynes azides. With indane-fused BOX ligand used, diverse array C–O atropisomers obtained with up 97% yield 99% ee. Control experiments showed that sequential...

We describe herein an N-heterocyclic-carbene-catalyzed atroposelective synthesis of axially chiral diaryl ethers. Through a sequentially enantioselective desymmetric process and kinetic resolution process, the products could be constructed in good yields with excellent enantiopurities. Both alcohols phenols were compatible this catalytic system. The carboxylic acids derived from esters proven to potential ligands for asymmetric synthesis, example, Rh(III)-catalyzed C–H functionalization.

Eine hoch enantioselektive Synthese von Arylglycin-Derivaten gelingt ausgehend N-PMP-geschützten α-Aryliminoestern durch asymmetrische Hydrierung mit einem Rhodium-Diphosphan-Katalysator (siehe Schema; PMP=para-Methoxyphenyl, cod=Cycloocta-1,5-dien). Die PMP-Gruppe kann leicht abgespalten werden, was zu enantiomerenreinen führt.

Abstract A regioselective synthesis of indole‐3‐carboxylic acid esters from anilines and diazo compounds has been realized by making use the pyrimidyl group‐assisted rhodium‐catalyzed CH activation CN bond formation. The reaction proceeds under mild conditions, exhibits good functional group tolerance scalability. Reutilization directing in resulting products provided an efficient strategy for further C‐7 functionalization indoles. Moreover, moiety could be readily removed as a leaving to...

Stereoselective synthesis of (<italic>Z</italic>)-α-boryl-crotylboronate is developed.

A palladium-catalyzed dearomative allylic alkylation of indoles with alkynes to construct indolenines C3-quarternary centers was reported. The in situ formed arylallene intermediate omitted the need install leaving groups on compounds and employ extra oxidants oxidize C–H bonds. reaction exhibited good functional group tolerance high atom economy. Moreover, further expanded synthesize pyrroloindolines furanoindolines.

The development of α,α-disubstituted crotylboronate reagents is reported. Chiral Brønsted acid-catalyzed asymmetric aldehyde addition with the developed E-crotylboron reagent gave (E)-anti-1,2-oxaborinan-3-enes excellent enantioselectivities and E-selectivities. With BF3·OEt2 catalysis, stereoselectivity reversed, (Z)-δ-boryl-anti-homoallylic alcohols are obtained Z-selectivities from same reagent. Z-crotylboron also participates in BF3·OEt2-catalyzed crotylation to furnish...

Abstract We report a dual function asymmetric catalysis by chiral phosphoric acid catalyst that controls both enantioselective addition of an achiral α‐vinyl allylboronate to aldehydes and pseudo‐axial orientation the group in transition state. The reaction produces dienyl homoallylic alcohols with high Z ‐selectivities enantioselectivities. Computational studies revealed minimization steric interactions between alkyl groups diol on boron influence substituent reagent occupy position

Abstract Hydrofunctionalization of alkynes is one the most efficient ways to access axially chiral styrenes with open‐chained olefins. While great advances have been achieved for 1‐alkynylnaphthalen‐2‐ols and analogues, atroposelective hydrofunctionalization unactivated internal lags. Herein we reported a platinum‐catalyzed hydrosilylation first time. With monodentate TADDOL‐derived phosphonite L1 used as ligand, various were in excellent enantioselectivities high E ‐selectivities. Control...

The development of a novel (Z)-α,δ-bisboryl-substituted crotylboron reagent is reported. Ni-catalyzed 1,4-diboration dienylboronate provided the targeted crotylboronate in good yield with high regio- and stereoselectivity. Chemo- stereoselective addition this to aldehydes followed by protection resulting secondary hydroxyl group gave TES-protected homoallylic alcohols bearing an alkyl vinyl boronate groups stereoselectivities.

Cu-catalyzed stereoselective synthesis of (<italic>E</italic>)-δ-silyl-<italic>anti</italic>-homoallylic alcohols from 1,3-dienylsilane was developed.

A rhodium-catalyzed hydroacylation of para-quinone methides (p-QMs) with salicylaldehydes has been disclosed. This method allows for the construction α,α-diaryl-2-hydroxy acetophenones through tandem C-H activation/C-C bond formation/aromatization process. Moreover, this unprecedented trisubstituted alkenes exhibits good yields broad functional group tolerance as well gram-scale capacity.

A diastereo- and enantioselective alkoxyallylation via phosphoric acid catalysis was reported. Under the developed conditions, either 1,2-syn- or 1,2-anti-alkoxyallylation adducts were obtained in good yields with high enantioselectivities.

Abstract We report herein the development of stereodivergent syntheses enantioenriched homoallylic alcohols using chiral nonracemic α‐CH 2 Bpin‐substituted crotylboronate. Chiral phosphoric acid ( S )‐ A ‐catalyzed asymmetric allyl addition with reagent gave Z ‐ anti ‐homoallylic excellent enantioselectivities and ‐selectivities. When enantiomeric catalyst R was utilized, stereoselectivity completely reversed E were obtained high ‐selectivities enantioselectivities. By pairing chirality...

Abstract We report herein a regiodivergent and enantioselective allyl addition to ketones with allenylsilanes through copper catalysis. With the combination of CuOAc, Josiphos‐type bidentate phosphine ligand PhSiH 3 , variety furnishes branched products in excellent enantioselectivities. The regioselectivity is completely reversed by employing P‐stereogenic BenzP*, affording linear enantioselectivities good Z ‐selectivities. ‐product could be converted E via catalytic geometric isomerization...

Cu-catalyzed highly stereoselective and enantiodivergent syntheses of (Z)- or (E)-β,γ-unsaturated ketones from 1,3-butadienyl silanes are developed. The nature the silyl group dienes has a significant impact on stereo- enantioselectivity reactions. Under developed catalytic systems, reactions acyl fluorides with phenyldiemthylsilyl-substituted 1,3-diene gave (Z)-β,γ-unsaturated bearing an α-tertiary stereogenic center excellent enantioselectivities high Z-selectivities, where...

A Cu-catalyzed addition of silicon or boron nucleophiles to vinylidene cyclopropanes is reported. The reactions generated propargylic silane products by forming a C-Si C-B bond at the terminal carbon allene moiety cyclopropanes. obtained and reagents are versatile intermediates that can undergo variety transformations give synthetically useful products. Preliminary mechanistic studies indicated copper enolate was involved in reaction process.

Anthranilic diamide derivatives are among the most important classes of synthetic insecticides. Moreover, 1,2,4-oxadiazole heterocycle, a bioisostere amide, has been extensively used in pesticides. In order to discover novel molecules with high insecticidal activities, series anthranilic analogues containing rings were designed and synthesised.A obtained, confirmed by 1 H 13 C nuclear magnetic resonance high-resolution mass spectrometry. The structure...

The syntheses of unsymmetrical 1,4-bifunctional allylboron reagents via Cu-catalyzed highly regio- and stereoselective 1,4-protoboration dienylboronates were developed. resulting allylboronates underwent chemoselective allylboration with aldehydes followed by oxidative workup to give diol products high diastereoselectivity. Transition state analysis revealed that the disfavored transition states suffer from either a severe A1,3 allylic strain or 1,3- syn-pentane interactions. Minimization...

A Cu-catalyzed stereoselective synthesis of (E)-γ',δ-bisboryl-anti-homoallylic alcohols was developed. The products contain an alkyl and a vinyl boronate group that can be directly used in variety subsequent transformations.