Cyclopropanation of active methylene compounds with β-alkoxycarbonyl vinylsulfonium salts

Copper acetate catalysed C–C bond formation en route to the synthesis of spiro indanedione cyclopropylpyrazolones

“…This resulted in product 3a in 45% yield, with a diastereomeric ratio of 4 : 1. The structure of 3″-methyl-1″,3′-diphenyldispiro[indene-2,1′-cyclopropane-2′,4″pyrazole]-1,3,5″(1″H)-trione (3a) was fully characterized by 1 H NMR and 13 C NMR spectroscopy. The 13 C NMR spectra showed peaks at δ 51.9, 50.6, and 42.2, which indicated a cyclopropyl ring.…”

“…12 A paper by Guo et al described a method for synthesising spiro-1,3-indanedionecyclopropanes from 1,3-indanedione and β-alkoxy carbonyl vinylsulfonium salts. 13 Electrocatalysed synthesis of polysubstituted spiro-1,3-indanedionecyclopropanes from 1,3-indanedione and aromatic aldehydes was accomplished by Mohammadi et al involving a sequential use of Michael addition, halogenation, and intramolecular ring-closing reactions. 14 Ghorbani-Vaghei and co-workers reported a one-pot, three-component domino reaction to synthesise spirocyclopropylindanediones using novel reagents (PBBS, TBBDA, PCBS and TCBDA).…”

Indane-1,3-Dione: From Synthetic Strategies to Applications

“…As alternative, o-iodoxybenzoic acid (IBX) can also be used as an oxidant, providing 4 in similar yield (92%) [19]. Several strategies were also developed to convert phthalic anhydride 8 into 4 using diethyl malonate 9 and montmorillonite KSF clay [20] or ethyl acetoacetate 11 in the presence of acetic anhydride and triethylamine [21]. In the case of substituted indane-1,3-diones, two distinct routes were developed depending on the substituents attached on the phthalic anhydrides.…”

“…Halogenation of indane-1,3-dione derivatives subsequent to their synthesis is not possible such that such derivatives can only be obtained by first introducing halogens onto their corresponding precursors. Notably, as a first synthetic approach, halogenated phthalic anhydrides were converted as indane-1,3-diones using ethyl acetoacetate, and a series of halogenated indane-1,3-diones 76-82 is presented in Scheme 8 [20,21,28,37,38,40,61]. Parallel to this, the strategy previously mentioned that AlCl 3 -promoted acylation of a benzoyl chloride derivative (83) with malonyl chloride 24 proved to be another effective approach to design chlorinated indane-1,3-dione derivatives (84) (see Scheme 8).…”

Diastereoselective Synthesis of Cyclopropanes from Carbon Pronucleophiles and Alkenes

“…[87][88][89][90][91][92][93][94] Only a handful of alkenyl sulfonium salts have been found to undergo cyclopropanation. [94][95][96][97][98][99][100] Given the relatively limited examples of cyclopropanation from unactivated alkenyl sulfonium salts similar to 5, we validated this potential mechanism by isolating 5 and resubjecting it to the substitution conditions. This experiment afforded the cyclopropane product 4 in 89 % yield, validating the kinetic competency of this species as an intermediate in cyclopropanation.…”