Michael brings the rings: An asymmetric intramolecular oxa-Michael reaction involving iminium activation has been developed. This provides enantioenriched 1,4-dioxane derivatives with up to 99 % yield and 98 ee. The method allows for concise stereoselective access stereodiverse, complex tetracyclic compounds containing a bicyclo[2.2.2]octan-2-one backbone multiple chiral centers.

A direct line: organocatalytic asymmetric vinylogous Michael addition of α,β-unsaturated γ-butyrolactams with ketones has been developed (see scheme; Boc=tert-butoxycarbonyl, Trp=tryptophan, Ts=4-toluenesulfonyl). The resulting products, 5-substituted 3-pyrrolidin-2-ones, could be obtained in excellent yields enantio- and diastereoselectivity. Detailed facts importance to specialist readers are published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or...

Abstract Both enantiomers of cis ‐ and trans ‐fused 3,4,4a,8a‐tetrahydro‐2H,5H‐pyrano[2,3‐b]pyran‐7‐carboxylates have been obtained in high diastereoselectivities enantioselectivities from the same starting materials using a tandem inverse‐electron‐demand hetero‐Diels–Alder/oxa‐Michael reaction catalyzed by modularly designed organocatalysts (MDOs). Diastereodivergence was achieved these reactions through direct control stereochemistry bridgehead atoms fused ring new MDOs self‐assembled both...

Abstract A highly diastereodivergent synthesis of tetrasubstituted cyclohexanes has been achieved using modularly designed organocatalysts (MDOs) which are self‐assembled in situ from amino acids and cinchona alkaloid derivatives. Diastereodivergence is realized through controlling the stereoselectivity individual steps a tandem Michael/Michael reaction. Up to 8 16 possible stereoisomers have successfully obtained high stereoselectivities MDOs for reaction an ensuing epimerization. The...

In this tutorial, reaction scopes, limitations and mechanisms of radical acylations are summarized discussed according to types catalytic systems.

The first highly efficient Michael addition of challenging α,α-disubstituted aldehydes to maleimides catalyzed by a simple bifunctional primary amine thiourea catalyst/benzoic acid system has been successfully developed generate quaternary carbon centers in high yields (up 99%) with excellent enantioselectivities (91–99%).

A general and direct organocatalytic asymmetric vinylogous Michael reaction of γ-butenolide with α,β-unsaturated ketones was investigated a multifunctional primary amine salt as catalyst. The enables straightforward access toward synthetically versatile γ-substituted butenolides from simple 2(5H)-furanone satisfactory yields, diastereo- enantioselectivities (up to 30 : 1 dr 95–99% ee).

A new thiourea-tertiary amine bifunctional catalyst derived from L-tert-leucine was developed and provides excellent stereocontrol in a novel direct Michael addition of 5H-oxazol-4-ones to α,β-unsaturated ketones with much broad substrate scope. The conjugate products chiral vicinal quaternary tertiary stereocenters can be easily transformed structurally interesting compounds or building blocks.

An asymmetric cyclization reaction of azadienes and azlactones was investigated by employing a Cinchona squaramide catalyst, which could afford series benzofuran-fused six-membered heterocycles containing α,α-disubstituted amino acid unit in highly diastereoselective (>20:1 dr) enantioselective (up to 99% ee) manner with good excellent yields 92%). A plausible pathway proposed explain the process.

We herein report the nickel-catalyzed enantioselective hydrofluoromethylation of enamides and enol esters with CH2FI as fluoromethyl source to enable diversity-oriented synthesis (DOS) chiral α-fluoromethylated amides well features wide functional group compatibility excellent enantioselectivity. The synthetic value this protocol was demonstrated by transformations resulted different scaffolds including amine, oxazoline, thiazoline, tetrahydroquinoline.

A diamine-catalyzed asymmetric tandem reaction between α,β-unsaturated ketones and rhodanine derivatives has been developed to synthesize various spirocyclic compounds with high stereoselectivities (up 99% ee >20 : 1 dr). The products obtained contain two pharmaceutically relevant features: the biologically active moiety embedded in a unit.

Aminocatalyzed asymmetric Diels-Alder reaction between 2,4-dienals and rhodanine/hydantoin derivatives via trienamine mechanism has been developed to synthesize various spirocyclic compounds with good yields (up 98%) excellent stereoselectivities 99% ee >19 : 1 dr).

Reported herein is an inverse-electron-demand oxa-Diels-Alder reaction that remotely β,γ-regioselective with β,γ-unsaturated amides and β,γ-unsaturated-α-ketoesters using a bifunctional catalyst. It can provide different kinds of dihydropyrans bearing three subsequent chiral carbon centers in good to high yield (61-99%) complete enantioselectivity (99 >99% ee). Furthermore, larger-scale experiment confirmed the reliability current reaction, further effective transformation product has been realized.

A vinylogous addition–cyclization reaction of cyclic α-amide enones with good yields and excellent regioselectivity catalyzed by cinchona squaramides has been reported. Using 4-aryl-3-butenyl N-acylpyrazoles as nucleophiles led to 1,4-selective γ-addition enones, 1,2-selective took place when 3-aryl-3-butenyl was used the donors. The 1,4- γ-adducts are then formed into corresponding highly stereoselective enantioselective fused bicyclic spirocyclic products intramolecular cyclization....

We herein disclose the Pd/amine dual-catalyzed ring-opening cross-coupling reaction between

Catalytic asymmetric Michael additions with curcumin derivatives were achieved by a new series of tertiary amine–thiourea organocatalysts to afford the adducts in high yields and excellent enantioselectivities.

An easy one-pot, multistep cascade reaction which could afford a series of substituted benzo[d]pyrido[2,1-b]oxazolidine and [1,3]oxazine derivatives in highly enantio- (up to 98% ee) diastereoselective (4:1 >20:1 dr) manner with generally good excellent yields 99%) has been developed. This well designed strategy be applied wide scope substrates under mild conditions simple operations.

A new highly efficient and reusable Cu-MOF has been developed for the regioselective synthesis of 1,2,3-triazoles <italic>via</italic> 1,3-dipolar cycloaddition organic azides to terminal alkynes under solvent-free conditions.

The construction of cyclobutanes has attracted much attention because its unique four-membered ring skeleton. Herein, we report the highly enantioselective direct vinylogous Michael reaction β,γ-unsaturated pyrazole amides and nitroolefin using a squaramide catalyst. Cyclobutane derivatives were obtained by subsequent cyclization in good yields (up to 85%) with excellent enantioselectivities 99% ee). Importantly, large-scale experiment confirmed reliability reaction. Furthermore, synthetic...

A PdII -catalyzed, domino enantioselective desymmetrizative coupling of 7-azabenzonorbornadienes with alkynylanilines is disclosed herein. This operationally simple transformation generates three covalent bonds and two contiguous stereocenters excellent enantio- diastereo-selectivity. The resulting functionalized indole-dihydronaphthalene-amine conjugates served as an appealing platform to streamline the diversity-oriented synthesis (DOS) other valuable enantioenriched compounds. DFT...

Novel construction methods for obtaining 3,4'-pyran spirooxindole heterocyclic skeletons have always been the focus of attention. Herein, we report a highly enantioselective inverse-electron-demand oxa-Diels-Alder cycloaddition reaction β,γ-unsaturated pyrazole amide and

Unter Iminiumaktivierung liefert die Titelreaktion enantiomerenangereicherte 1,4-Dioxan-Derivate in Ausbeuten bis 99 % und mit zu 98 ee. Die Methode bietet einen schnellen stereoselektiven Zugang stereochemisch diversen komplexen Tetracyclen Bicyclo[2.2.2]octan-2-on-Kern mehreren Chiralitätszentren.