An efficient [4 + 3] cycloaddition reaction of D–A cyclopropanes with dienes has been successfully developed. The proceeds well various dienolsilyl ethers in the presence Lewis acid, delivering a variety cycloheptenes and [n,5,0]carbobicycles excellent stereoselectivity. asymmetric version this is also realized using newly designed chiral Cy-TOX ligand, providing new approach to access optically active [n,5,0]carbobicycles. Mechanisic study reveals that involves stepwise pathway, which...

Designing armory: The side-arm-modified In-TOX/NiII complex was identified as a highly efficient and stereoselective catalyst for the [3+3] cycloaddition of aromatic azomethine imines with cyclopropanes (see picture). Density functional calculations control experiments revealed that directing effect side arm through π interactions is crucial to stereochemical control. As service our authors readers, this journal provides supporting information supplied by authors. Such materials are peer...

Stereocontrol in the synthesis of structurally complex molecules, especially those with all-carbon quaternary stereocenters, remains a challenge. Here, we reported preparation class tetracyclic cyclopenta-fused spiroindoline skeletons through Cu(II)-catalyzed intramolecular [3 + 2] annulation reactions donor–acceptor cyclopropanes indoles. Both cis- and trans-diastereomers spiroindolines are accessed high selectivities by altering remote ester groups cyclopropanes. The origins this...

Abstract A ligand‐promoted catalytic [4+2] annulation reaction using indole derivatives and donor‐acceptor (D‐A) cyclobutanes is reported, thus providing an efficient atom‐economical access to versatile cyclohexa‐fused indolines with excellent levels of diastereoselectivity a broad substrate scope. In the presence chiral SaBOX ligand, enantioselectivity was realized up 94 % ee. This novel synthetic method applied as general protocol for total synthesis (±)‐akuammicine formal (±)‐strychnine...

Abstract Donor‐acceptor (DA) cyclopropanes are particularly useful synthetic building blocks, which have been widely applied in the total synthesis of natural products and important chiral molecules organic synthesis. The asymmetric ring‐opening reactions racemic DA cyclobutanes, for example, aryl‐substituted 1,1‐cyclopropane diesters 1,1‐cyclobutane diesters, with nucleophiles provides versatile access to optically active γ‐ δ‐functionalized carbon skeletons, as well kinetic resolution...

The first catalytic enantioselective ring-opening reaction of donor-acceptor cyclopropanes with water is described. By employing Cy-TOX/Cu(II) as catalyst, the performed very well over a broad range substrates, leading to products in 70-96% yields up 95% ee under mild conditions. current method provides new approach direct access γ-substituted GBH derivatives efficiently. Importantly, Cu(ClO4)2·6H2O proves serve both Lewis acid and source water, which affords fine system controllably release...

A highly diastereoselective and enantioselective Cu(II)/SaBOX-catalyzed [2 + 2] cycloaddition of methylidenemalonate multisubstituted alkenes was developed to furnish optically active cyclobutanes in high yields with >99/1 dr up >99% ee. By application the newly method, total synthesis (+)-piperarborenine B completed eight steps from olefin 17% overall yield 99%

Abstract A facile and efficient method to produce optically pure benzofuroindolines, especially those without 3‐substituents that are susceptible rearomatization, through [3+2] annulation of indoles with quinones is described. The suitable combination a BOX ligand Cu II hydrate complex freshly activated molecular sieves functions give controllably dynamic release water, which enables the success this reaction. This reaction can be performed on gram scale only 0.5 mol % catalyst loading.

In recent years, covalent organic framework (COFs) have emerged as a new class of photocatalysts due to their structural diversity, band gaps tunability, and high porosity structures. Among these, β-keto-enamine COFs are an important type that benefited from stability, low-cost convenient synthesis, intrinsic charge-separation ability, excellent visible-light-absorption ability. The 1,3,5-triformylphloroglucinol (Tp)-based the most primary linkage in assembling COFs, also named Tp-COFs....

The title reaction provides a promising approach for the synthesis of chiral flavanones with broad substrate scope and is tolerant to air moisture. Good excellent enantioselectivities high yields were achieved most substrates under mild conditions. Detailed facts importance specialist readers are published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They made available submitted by authors. Please note: publisher responsible content...

Triangulation method: The catalytic enantioselective cyclopropanation of multisubstituted olefins with phenyliodonium ylide malonate has been achieved in the presence a chiral bisoxazoline copper(I) complex (see scheme). A wide range substrates undergo reaction to provide optically active 1,1-cyclopropane diesters high yield up >99 % ee. rationale for induction proposed.

The first highly diastereoselective and enantioselective catalytic formal [4 + 3] cycloaddition of 1,1-cyclobutane diester with nitrone has been developed. Sterically hindered chiral SaBOX/Cu(II) complex promotes the reaction efficiently a broad substrate scope, producing range multifunctionalized optically active 1,2-oxazepanes excellent stereocontrol (up to >99/1 dr 97% ee).

A one-pot asymmetric synthesis of 1,2,3,4-tetrahydrocarbazoles has been developed via an enantioselective [3 + 3] annulation 2-alkynylindoles and donor–acceptor cyclopropanes. In the presence chiral Lewis acids as catalysts, a series optically active tetrahydrocarbazoles were furnished in high yields (63–87%) with good to excellent levels enantioselectivity (up 94% ee).

Tetracyclic indolines are ubiquitous skeletons in bioactive natural products and pharmaceuticals, efficient methods for their enantioselective synthesis highly desired. Here, we report an three-component formal [2 + 2 2] cycloaddition reaction between indoles, 2,3-dihydropyran, methylene malonates rapid construction of optically active tetracyclic bearing four continuous stereocenters. Although the optimal catalyst Cu(II)/BOX displays only moderate enantioselectivities either cyclobutanation...

Highly efficient synthesis of chiral tetrasubstituted 2,3-dihydrofuran derivatives has been realized by Cu-catalyzed asymmetric [4 + 1] cycloadditions α-benzylidene-β-ketoester with a diazo compound. Following this methodology, series optically active multifunctionalized dihydrofurans were prepared in high yield up to 96% ee and 99/1 dr.

Abstract A novel formal [2+2+2] strategy for the stereoselective elaboration of polycyclic indole alkaloids is described. Upon treatment with catalyst InCl 3 (5 mol %), tryptamine‐derived enamides reacted readily methylene malonate, thus enabling rapid and gram‐scale access to versatile tetracyclic spiroindolines excellent diastereoselectivity (21 examples, up 95 % yield, d.r.>95:5). This provides a concise approach isolated from Strychnos myrtoides , as demonstrated by short synthesis...

Abstract Facile and effective access for the asymmetric construction of useful important skeleton bicyclic N,O‐acetals is described. Cu II /SaBOX could catalyze reaction β,γ‐unsaturated α‐ketoesters with cyclic enamines efficiently, thus affording desired products in excellent yields stereoselectivities (21 examples; up to 99 % yields; >95:5 d.r.; 95–99 ee ). This can be well performed on gram scale, even only 1 mol catalyst loading. The single‐crystal structures copper complexes lead a...

The novel rose-shaped S-scheme heterojunction photocatalyst (β-Bi 2 O 3 /Bi 2.33 )/TiO is successfully prepared by a green DES-mediated strategy and remarkably promotes the efficiency for antibiotics degradation water splitting into hydrogen.

A photocatalyst-free, metal-free visible light-promoted thiol-ene/oxidation tandem reaction for sulfoxide synthesis has been developed under mild conditions with air as oxidant. Broad substrate scope well gram-scale enables...

The first catalytic asymmetric three-component allylation of aldimines has been developed. In the presence L-ramipril acid-oriented N,N′-dioxide–ScIII complex catalyst, a range homoallylic amines were formed in excellent enantioselectivities (up to 97 % ee) with good yields from corresponding aldehydes, 2-aminophenol and allyltributyltin (see scheme).

Abstract A type of C 2 ‐symmetric secondary amine amide catalysts were developed for the asymmetric Michael addition 4‐hydroxycoumarin to α,β‐unsaturated ketones. series important biologically and pharmaceutically active compounds obtained in excellent yields (up 99 %) with high enantioselectivities 89 % ee ) under mild conditions. In addition, enantiopure product could be by a single recrystallization. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Reich an Armen: Der mit einem Seitenarm modifizierte In-TOX-NiII-Komplex wurde als hoch effizienter und stereoselektiver Katalysator der [3+3]-Cycloaddition von aromatischen Azomethin-Iminen Cyclopropane identifiziert (siehe Bild). Dichtefunktionalrechnungen Kontrollexperimente zeigen, dass den stereochemischen Verlauf über π-Wechselwirkungen entscheidend bestimmt. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials...