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Herein, we present an efficient strategy for the synthesis of spiro(indenyl)cyclohexadienones through radical‐promoted reaction of 2‐alkynyl biaryls with sodium sulfinates under electrochemical conditions. The reaction involves sulfonylation and dearomative ipso‐cyclisation in a domino fashion. This approach features the use of readily accessible precursors, wide functional group tolerance and external oxidant‐free reaction conditions. The practicality of the method was also illustrated by scale‐up reaction and further diversification of the product. [ABSTRACT FROM AUTHOR]

Herein, we present the first annulation reaction of (N‐aryl)‐alkynyl sulphonamides leading to sultams or spirocyclic sultams. The selective formation of aforesaid products is based on the variable reactivity, intramolecular ortho‐cyclization or dearomative ipso‐annulation, guided by the substituent on N‐aryl group of the substrate. The ortho‐annulation is mediated by electrophile, while the ipso‐annulation is promoted by the radical, enabling the functionalization (selenyl or iodo) on sultams. The synthetic potential of this method is illustrated by modifications of the functional groups present in the products obtained. [ABSTRACT FROM AUTHOR]

Rh(III)‐catalyzed cascade oxidative C−H functionalization/aza‐annulation of indole and pyrrole‐N‐carboxamides with 1,3‐enynes involving 1,4‐rhodium migration is disclosed. This [4+1] annulation protocol provides an approach for the synthesis of imidazo[1,5‐a]indol‐3(2H)‐ones from easily accessible substrates. Moreover, sulfonamides are also found to be well compatible in this method, leading to the corresponding benzo[d]sultams. The efficacy of this protocol is highlighted by handy downstream conversions of the dienyl‐sultam. [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis of functionalized dihydro‐benzo[b]fluorenones through a manganese‐mediated cascade radical cyclization of β‐alkynyl propenones [1,6‐enynes] with arylboronic acids. In the present strategy, the in‐situ generated aryl radical undergoes chemo‐selective addition followed by 5‐exo‐trig cyclization. The reaction is emphasized by high atom‐ and step‐economy with the construction of three new C−C bonds to access the dihydrobenzo[b]fluorenones in 68–81% yield under mild reaction conditions. The synthetic efficacy of the developed method is evidenced by the construction of new C−C and C−N bonds. [ABSTRACT FROM AUTHOR]

A novel and efficient domino annulation for the construction of unrevealed polycyclic 3, 4‐fused indoles involving rhodium(III)‐catalyzed alkyne insertion followed by aza‐Michael addition is presented. A variety of N‐(pivaloyloxy)arylamides and N‐(pivaloyloxy)‐1H‐indole‐1‐carboxamides were utilized in this annulation with 4‐alkynyl‐3‐alkenyl indoles. [ABSTRACT FROM AUTHOR]

A novel one-pot [4+2]-benzannulation approach to substituted carbazoles is accomplished by acid-catalyzed C3-propargylation of 2-alkenyl/aryl indoles with 1-aryl propargylic alcohols, followed by cycloisomerization. A variety of 2-alkenylated indoles and 2-aryl/heteroaryl indoles successfully participated in this tandem reaction with 1-aryl/heteroaryl propargylic alcohols to provide diversely substituted and annulated carbazoles, as well as an aza[5]helicene. [ABSTRACT FROM AUTHOR]

The asymmetric synthesis of two naturally occurring 5-hydroxy- γ-butyrolactones, (4 R,5 R)-5-hydroxy-4-decanolide ( 1a) and (−)-muricatacin ( 2), is described using a general alkyne-mediated strategy. The key steps involved are Sonogashira coupling for the desired carbon-chain extension followed by Sharpless asymmetric dihydroxylation to construct the hydroxy-lactone framework. [ABSTRACT FROM AUTHOR]

The stereoselective total synthesis of dinemasone A has been accomplished. The key reactions, Sharpless asymmetric epoxidation, lithium-mediated epoxy alcohol opening, and double-intramolecular hetero-Michael addition, gave access to dinemasone A from lactic acid esters. The stereochemistry at the spiro carbon was determined using extensive NMR studies. [ABSTRACT FROM AUTHOR]

The synthesis of 3-aryl-4-nitrocyclohexanones has been achieved from the Morita-Baylis-Hillman adducts of β-arylnitroethylenes. The strategy involves proline-catalyzed diastereoselective intramolecular Michael addition to obtain 3,4- trans-disubstituted cyclohexanones. This method provides a facile access to (±)-epibatidine analogues. [ABSTRACT FROM AUTHOR]

An efficient approach has been described for the synthesis of 3,5-disubstituted isoxazoles from propargylic alcohols. The strategy involves a one-pot p-TSA-catalyzed N-propargylation of protected hydroxylamines followed by a TBAF-mediated detosylative 5- endo- dig cyclization. The method was successfully used for the synthesis of various 3,5-disubstituted isoxazoles. [ABSTRACT FROM AUTHOR]

An efficient synthetic strategy for the synthesis of diversely 2,3-disubstituted benzofurans is described. This method is based on the use of propargylic alcohols generated from TBS-protected ortho-hydroxy benzaldehydes as starting materials and allows a library of 2,3-disubstituted benzofurans to be built. The procedure consists of one-pot nucleophilic substitution, TBS-deprotection, and exo- dig cycloisomerization. [ABSTRACT FROM AUTHOR]

The first enantioselective total synthesis of a polyhydroxylated macrolide, (+)-seimatopolide A, was achieved. The key reactions, Sharpless asymmetric dihydroxylation, Yamaguchi esterification, and ring-closing metathesis, provided easy access to the target molecule from L-aspartic acid. Further, the absolute stereochemistry of the natural product has also been revised. [ABSTRACT FROM AUTHOR]

A graphical abstract of the study "Novel [4 + 2]-Benzannulation to Access Substituted Benzenes and Polycyclic Aromatic and Benzene-Fused Heteroaromatic Compounds," is presented.

A correction to the article "One-Pot Sequential Propargylation/ Cycloisomerization: A Facile [4+2]- Benzannulation Approach to Carbazoles" that was published in the previous issue of the journal is presented.

A novel one-pot [4 + 2]-benzannulation approach to substituted carbazoles is accomplished by acid-catalyzed C3-propargylation of 2-alkenyl/aryl indoles with 1-aryl propargylic alcohols, followed by cycloisomerization. [ABSTRACT FROM AUTHOR]

(4R,5R)-5-hydroxy-4-decanolide (IIIa) and (-)-muricatacin (IIIb) are stereoselectively synthesized starting in a new six-step reaction sequence involving the Sonogashira coupling for the desired carbon-chain extension followed by Sharpless asymmetric dihydroxylation to construct the hydroxy-lactone framework as key steps. [ABSTRACT FROM AUTHOR]

A novel aza-annulation of 2-en-4-ynyl azides, derived from MBH-acetates of acetylenic aldehydes, to synthesized substituted pyridines is developed. [ABSTRACT FROM AUTHOR]

The two-step process can be applied to the preparation of a broad spectrum of target compounds. [ABSTRACT FROM AUTHOR]

The article presents chemical equations for the article "A Metal-Free Tandem C-C/C-O Bond Formation Approach to Diversely Functionalized Tetrasubstituted Furans" by C. R. Reddy and others, published in the 2013 issue of the "Journal of Organic Chemistry."