An unconventional, highly stereoselective, and regioselective intramolecular oxypalladation/acyloxylation cascade of alkyne-tethered cyclic 1,3-diones has been developed. This atom-economic Pd(II)-catalyzed annulation reaction is initiated by the oxypalladation alkyne with an internal carbonyl group via 5-exo-dig cyclization instead conventional acetoxypalladation pathway. In this process, carboxylic acid plays a pivotal role in generation active cationic Pd-complex subsequent acyloxylation...

The first reverse regioselective intermolecular annulation of aryl substituted 2-acetylenic ketones with O-substituted N-hydroxybenzamides or acrylamides followed by tandem cyclization via ruthenium-catalyzed C-H activation, is reported. Excellent selectivity alkyne insertion was induced the weak coordination between carbonyl group and ruthenium complex. This highly efficient practical reaction has a broad range substrate scope excellent functional-group tolerance. provides wide polycyclic...

Rhodium-catalyzed asymmetric hydrogenation of alkyne-tethered cyclohexadienones enables highly regio- and enantioselective reductive cyclization to afford cis-hydrobenzofurans cis-hydroindoles in high yields. Desymmetrization 1,3-diyne-tethered was also explored, wherein the intramolecular coordination a Rh complex with cyclohexadienone ring induces exclusive regioselectivity. Mechanistic studies including hydrogen–deuterium crossover experiments suggested that hydrogen activation is...

The formal total synthesis of pentacyclic core alkaloid, (±)-cephalotaxine is achieved in nine steps from known 2-allylpyrrolidine-2-carboxaldehyde using aryne insertion reaction as a key step 10% overall yield. developed novel strategy enabled easy access to cephalotaxine congeners.

Cp*Co(III)-catalyzed C-H functionalization cascade of N-methoxyamides with alkynedione has been reported for the synthesis indolizidine scaffolds under redox-neutral conditions. The reaction displays broad functional group tolerance along excellent yield. proceeds kinetically relevant bond activation through carboxylate assistance diastereoselectivity and complete opposite selectivity respect to alkyne insertion.

The highly efficient and expedient route for the syntheses of 2-aroyl benzofurans has been developed via cascade [2+2] followed by a [4+1] annulation on arynes. overall transformation proceeded through formation ortho-quinone methide insertion transient aryne into N, N-dimethylformamide subsequent trapping with sulfur ylide. Moreover, this broad range substrate scope high functional-group tolerance. This new reaction was successfully utilized in synthesis potent CYP19 aromatase inhibitor...

The catalytic asymmetric borylation of conjugated carbonyls followed by stereoselective intramolecular cascade cyclizations with in situ generated chiral enolates are extremely rare. Herein, we report the enantioselective Cu(I)-catalyzed β-borylation/Michael addition on prochiral enone-tethered 2,5-cyclohexadienones. This desymmetrization strategy has a broad range substrate scope to generate densely functionalized bicyclic enones bearing four contiguous stereocenters excellent yield,...

A mild and efficient Pd-catalyzed arylative domino carbocyclization of cyclohexadienone-containing 1,6-enynes is described. The reaction tolerates a variety functionalized boronic acids to afford cis-fused bicyclic framework containing an α,β-unsaturated ketone with excellent regio- diastereoselectivity in good yields. tandem process proceeds β-arylation propargylic ether followed by conjugate addition vinyl palladium intermediate subsequent protonolysis enolate.

A novel insertion reaction of N-tosylacetimidates and N-tosylacetimidamides onto arynes via a benzocyclobutene intermediate followed by ring cleavage is developed to afford o-benzylbenzoic acid derivatives in good yields. Interestingly, the use cyclic 2-sulfonyliminoindolines provided two distinct products such as azepanimines [2 + 2] cycloaddition indolamines protonation based on solvent medium.

Herein, we have developed a Pd(II)-catalyzed cyclization of prochiral alkyne-tethered malononitriles to access five-membered carbocycles having the nitrile-containing all-carbon quaternary center. The reaction pathway involves trans-acetoxypalladation, nitrile group insertions...

Abstract Catalytic hydrocupration of unsaturated carbon‐carbon bonds to generate organometallic nucleophiles has recently become an attractive alternative conventional stoichiometric reagents in the stereoselective synthesis. Herein, we have developed efficient and economical method synthesize enantiopure α ‐hydroxy allyl ketones via a copper hydride (CuH)‐catalyzed hydroacylation alkoxyallenes, significant advancement given scarcity reports on such scaffolds literature. DFT calculations...

Abstract Catalytic hydrocupration of unsaturated carbon‐carbon bonds to generate organometallic nucleophiles has recently become an attractive alternative conventional stoichiometric reagents in the stereoselective synthesis. Herein, we have developed efficient and economical method synthesize enantiopure α ‐hydroxy allyl ketones via a copper hydride (CuH)‐catalyzed hydroacylation alkoxyallenes, significant advancement given scarcity reports on such scaffolds literature. DFT calculations...

The first synthesis of dolabelide C (1), a cytotoxic marine macrolide, is reported utilizing phosphate tether-mediated approach. Bicyclic phosphates (S,S,SP)-5 and (R,R,RP)-5 serve as the central building blocks for construction two major 1,3-anti-diol subunits in 1 through selective cleavage pathways, regioselective olefin reduction, cross-metathesis. Overall, phosphate-mediated processes provided copious amounts both allowing detailed RCM macrocyclization study to 24-membered macrolactone 1.

Organocatalytic asymmetric desymmetrization of prochiral cyclohexane-1,3-diones has been demonstrated through the merging iminium and enamine activation.

A practical and enantioselective total synthesis of hyacinthacine A1 is achieved involving syn allylic epoxide opening with retention using Pd catalysis “domino” hydrogenation (five steps in one pot) sequences.

A combination of "chiron" and "asymmetric" approaches is utilized to construct the southern (C9−C25) region marine natural product spirastrellolide B. The key functionalities are derived from d-glucose Sharpless asymmetric epoxidation dihydroxylation.

An efficient synthesis of (−)-tetrahydrolipstatin (THL) is reported. This method takes advantage a phosphate tether-mediated, one-pot, sequential RCM/CM/hydrogenation protocol to deliver THL in eight total steps from readily prepared (S,S)-triene. The strategy incorporates selective cross-metathesis, regioselective hydrogenation, regio- and diastereoselective cuprate addition, Mitsunobu inversion for installation the C5 formamide ester subunit.

A highly regioselective and stereoselective cascade annulation of indoles with C2-symmetric enone tethered-cyclohexadienones provides rapid access to complex indole alkaloid-like scaffolds in high yields. Interestingly, a different reaction course was observed 3-substituted giving C-2/N products similar complexity via intramolecular aza-Michael addition. This desymmetrization approach is practical allows atom-economical synthesis natural product-like molecules containing several contiguous...

An unconventional Ag(I)-catalyzed intramolecular cyclopropanation of prochiral alkyne-tethered cyclohexadienones has been developed using simple perchloric acid as an external oxidant. The transformation involves the formation a perchloryloxy vinyl-silver species, which then proceeds through either conjugate addition or α-oxo silver carbene pathway to yield cyclopropane fused tricyclic enones with high diastereoselectivity. In case C-tethered cyclohexadienones, reaction further via mediated...

Abstract Enantioselective desymmetrization of prochiral 1,3‐cyclodiketones is the most convenient and highly desired transformation to access densely functionalized, enantiomerically enriched scaffolds with multiple chiral centers. In recent years, organocatalysis has made significant progress in this research area along other traditional metal‐ or enzyme‐catalyzed reactions. This mini‐review provides an overview developments domain organocatalytic enantioselective a brief discussion about...

In this work, we have developed an unconventional and highly enantioselective solvent-promoted Rauhut–Currier cyclization of enal-tethered cyclohexadienone by exploiting the reactivity a simple Jørgensen–Hayashi catalyst through merging iminium enamine activation. This asymmetric desymmetrization reaction has broad substrate scope in good yields with high to excellent enantioselectivity. DFT calculations suggest that elimination alkoxy group is rate-limiting step it proceeds proton...

A versatile three-step, one-pot, sequential reaction protocol involving ring-closing metathesis, cross-metathesis, and chemoselective hydrogenation is reported. This phosphate tether-mediated process occurs without intermediate isolation, chemoselective, governed by stereoelectronic properties innate to tethers, which ultimately act preserve the integrity of bisallylic, bicyclic for subsequent nucleophilic additions. Overall, this can be used efficiently generate advanced polyol synthons.

Catalytic tandem diastereoselective desymmetrization of cyclohexadienone-containing 1,6-enynes has been achieved through copper-catalyzed [3 + 2]-cycloaddition followed by ketenimine formation and subsequent intramolecular conjugate addition. The cascade reaction provides cis-hydrobenzofurans in good yields with excellent diastereoselectivity. exo- or endo-selectivity bicyclic scaffolds depends on the selection base reaction. In addition, N-tethered products further transformed into...