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Abstract: An efficient asymmetric dearomative [3+2] cycloaddition reaction of 2‐nitroindoles and 2‐nitrobenzothiophenes with 3‐isothiocyanato oxindoles was developed by using a chiral Zn(OTf)2/bis(oxazoline) complex as a catalyst. With the developed protocol, a range of enantioenriched complex heterocyclic compounds containing three contiguous stereocenters, one of which is spirocyclic center, could be obtained in quantitative yields with excellent diastereo‐ and enantioselectivities. The potential utility of this method was showcased by the diverse transformations of the products. [ABSTRACT FROM AUTHOR]

Abstract: A highly diastereo‐ and enantioselective dearomative [3+2] cycloaddition reaction of 3‐nitrobenzothiophenes and 3‐nitrothieno[2,3‐b]with 3‐isothiocyanato oxindoles is developed. The reaction is catalyzed by the chiral Zn(OTf)2/bis(oxazoline, and is the second example of a catalytic asymmetric dearomative cycloaddition reaction of 3‐nitrobenzothiophene derivatives. A range of complex heterocyclic compounds containing three contiguous stereocenters, one of which is spirocyclic center, can be obtained in quantitative yields with excellent stereoselectivities. [ABSTRACT FROM AUTHOR]

A highly diastereo- and enantioselective [3+2] cycloaddition reaction of N-2,2,2-trifluoroethylisatin ketimines and 3-alkenyl-5-arylfuran-2(3H)-ones was developed with 1 mol% thiourea–tertiary amine as the catalyst. A series of spiro[pyrrolidin-3,2′-oxindoles] bearing four consecutive stereocenters, including two vicinal spiro-quaternary chiral centers, were efficiently obtained with excellent results (up to ＞99% yield, ＞20 : 1 dr, and ＞99% ee). [ABSTRACT FROM AUTHOR]

The first organocatalytic asymmetric sequential allylic alkylation–cyclization of Morita–Baylis–Hillman carbonates and 3-hydroxyoxindoles has been developed to afford spirooxindoles bearing α-methylene-γ-butyrolactone motifs in 25–85% yield, 60–94% ee and up to ＞20 : 1 diastereoselectivity. [ABSTRACT FROM AUTHOR]

The front cover picture provided by Wei ‐ Cheng Yuan and co ‐ workers illustrates the recent advances in catalytic asymmetric cascade reactions with α ‐ isothiocyanato compounds as new type of versatile reagents. In recent years, numerous catalytic asymmetric reactions, including asymmetric cascade aldol/cyclization, Mannich/cyclization, Michael/cyclization, [3+2] cyclization with allenic esters, [3+2] cyclization with 2 ‐ butynedioic acid diesters, [3+2] cyclization with azodicarboxylates, as well as self ‐ cyclization/addition with aziridines, were successfully developed by using α ‐ isothiocyanato compounds. Details can be found in the review on pages 3007 – 3031 (W. ‐ Y. Han, J. ‐ Q. Zhao, J. Zuo, X. ‐ Y. Xu, X. ‐ M. Zhang, W. ‐ C. Yuan, Adv. Synth. Catal.­ 2015, 357, 3007 – 3031; DOI: 10.1002/adsc.201500264). [ABSTRACT FROM AUTHOR]

A base mediated 1,3-dipolar cycloaddition reaction of methyl 1,4-dioxo-1,4-dihydronaphthalene-2-carboxylate with nitrile oxides in situ generated from N -hydroximoyl chlorides was achieved. With this developed protocol, a range of structurally diverse naphtho[2,3- d ]isoxazole-4,9(3a H ,9a H )-dione derivatives were smoothly obtained in high yields (up to 95%) with up to >20:1 regioselectivities and >20:1 diastereoselectivities under mild conditions. The promising applicability of the protocol was also demonstrated by the further transformations. [ABSTRACT FROM AUTHOR]

An efficient [4+1] cycloaddition of ortho -hydroxyphenylsubstituted para- quinone methides and sulfur ylides was achieved under the catalyst-free condition. With this developed protocol, a series of trans -2,3-dihydrobenzofurans were obtained in excellent yields (up to 99%) with high diastereoselectivities (>20:1 dr). The usefulness of the protocol was also demonstrated by the versatile conversions of the 2,3-dihydrobenzofurans into other functionalized benzofurans. [ABSTRACT FROM AUTHOR]

A convenient and efficient method for the synthesis of furoxan derivatives from α-nitro-ketoximes and sulfonyl chlorides is reported. A wide variety of furoxan derivatives were smoothly obtained in good yields via a DABCO-mediated cascade sulfonylation/cyclization process under mild conditions. The usefulness of this method was also demonstrated by the conversions of the furoxan products into other promising compounds. [ABSTRACT FROM AUTHOR]

A range of structurally diverse chiral spiro[imidazolidine-2-thione-4,3′-oxindole] compounds could be obtained via a domino Mannich-cyclization reaction of 3-isothiocyanato oxindoles and imines with commercial quinine as catalyst under mild conditions. The protocol is significantly characterized by simple process, easily available catalyst, high reactivity, low catalyst loading (1 mol %), and good to excellent diastereo- and enantioselectivity (up to>99:1 dr and 97% ee). A plausible dual activation working model was tentatively proposed to account for the stereochemistry of the domino Mannich-cyclization process. [ABSTRACT FROM AUTHOR]

Abstract: The first K2CO3-catalyzed 1,3-dipolar cycloaddition/dehydrogenation of azodicarboxylates with azomethines was developed and a wide range of unsaturated 1,2,4-triazolines have been successfully prepared in good yields (up to 93%). [Copyright &y& Elsevier]

Spirocyclic oxindoles are obtained by the title cyclization reaction with good to excellent diastereo- and enantioselectivities. [ABSTRACT FROM AUTHOR]

The first organocatalytic asymmetric cyclization of the title compounds is presented. [ABSTRACT FROM AUTHOR]