The Reaction of some Carbonyl and Thiocarbonyl Compounds with Prenyl‐ and Crotyllithium in Tetrahydrofuran Solution

Rautenstrauch, Valentin

doi:10.1002/hlca.19740570226

Cited by 57 publications

(15 citation statements)

References 37 publications

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“…This is supported by the reaction of thiocarbonyl compounds with ( Z ) -or @)-substituted prop-2-enyl Grignard reagents, in which retention of the configurafion was observed [43]. For the carbophilic addition of allylic organometallics, even more mechanistic hypotheses were presented, such as reaction through a six-center cyclic intermediate [51-541, via an ate complex 1551 1561, a thiophilic addition followed by a [2,,3]-sigmatropic shift [47], and Scheme 4 10 11 bimolecular electrophilic substitution (&2' mechanism) [57] [58]. Thuillier and coworkers [59] showed that the sigmatropic rearrangement does not occur in the reactions of ally1 Grignard reagents and thiocarbonyl compounds.…”

Section: Addition Reactions With Organocupratementioning

confidence: 97%

New Addition Reactions of Organometal Compounds with 4,4‐Dimethyl‐1,3‐thiazole‐5(4H)‐thiones

Shi¹,

Heimgartner²

1996

Helvetica Chimica Acta

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Dedicated to Professor H. Suschifzky on the occasion of his 80th birthday (I.XII.95) Addition reactions of organometallic reagents with 4,4-disubstituted 1,3-thiazole-5(4H)-thiones were studied.Whereas the reactions with alkyllithium and alkyl Grignard reagents occurred in the thiophilic manner, the carbophilic addition was observed with allyllithium and ally1 Grignard reagents. A radical reaction mechanism is proposed for rationalizing these observations (Scheme 5). A radical cyclization of the prepared 5-allyl-4,5-dihydro-1,3-thiazole-5-thiol derivatives yielded 1,6-dithia-3-azaspiro[4.4]non-2-enes ( -C=S).In the reactions of 1 with organometallics, it was shown that organolithium reagents undergo thiophilic addition exclusively [ 101. In contrast, organocuprates only afforded products of carbophilic addition [ 111 [ 121. Products of carbophilic and/or thiophilic attack were obtained from the reaction of 1 with Grignard reagents, depending on the nature of the Grignard reagent and the solvent used in the reaction [lo].In this paper, we report on further results from addition reactions of organometallics with a variety of 2-alkyl-substituted 1,3-thiazole-5(4H)-thiones, in which some exceptions of the previously formulated rules were observed, and possible reaction mechanisms are discussed. Furthermore, the radical cyclization of some of the prepared 5-alkenyl-4,5-dihydro-1,3-thiazole-5(4H)-thiioles was studied.

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Section: Addition Reactions With Organocupratementioning

confidence: 97%

New Addition Reactions of Organometal Compounds with 4,4‐Dimethyl‐1,3‐thiazole‐5(4H)‐thiones

Shi¹,

Heimgartner²

1996

Helvetica Chimica Acta

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“…Tentatively, the structure of this product was proposed as the endo methylsulfanyl derivative 4 4 11a (Scheme 4). In analogy to the series of compounds 9, the thiolate 10, upon treatment with allyl iodide and 2,4-dinitrofluorobenzene, was transformed into 11b and 11c, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…Recently, it has been demonstrated that the 2 additions of Grignard reagents with aromatic thioketones proceed via a multistep reaction mechanism, including single electron transfer (SET) processes [3]. In the case of adamantanethione (1a), the addition of prenyllithium occurs in a carbophilic manner, and the quenching with methyl iodide leads to the corresponding methyl sulfane 2 [4] (Scheme 1). …”

Section: Introductionmentioning

confidence: 99%

Reactions of polycyclic thioketones with a phosphonylated carbanion

Mlostoń

Obijalska

Urbaniak

et al. 2008

Heteroatom Chemistry

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Polycyclic, nonenolizable cycloaliphatic thioketones 1a and 1b react smoothly with the lithium salt of diethyl methylphosphonate 7 in THF solution at −40°C to afford products of the carbophilic attack exclusively. Quenching of the obtained lithium thiolates with alkyl iodides yields sulfanes of type 9 or 11, respectively, in good yields. 1‐Fluoro‐2,4‐dinitrobenzene was shown to act as an arylating agent. In the case of the “cage” thioketone 1b, the carbanion of salt 7 approaches the CS bond from the exo‐side exclusively. In contrast to the parent carbonyl compounds, thioketones 1 show no tendency to undergo the conversion analogous to the Horner–Wadsworth–Emmons reaction, which would result in the formation of an olefinic product. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:182–187, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20390

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“…Artemisia triene (1) [lo], artemisia ketone (2), artemisia alcohol (4) and its acetate 5 are known products [8] [9]. We identified the epoxide 3 of artemisia ketone for the first time in nature.…”

mentioning

confidence: 99%

“…- Epoxy-3,3,6-trimethyl-I-hepten-4-one ('epoxy-artemisia ketone'; 3). Artemisid ketone (2) was prepared as described in [8] or [9]. A mixture of 0.45 g of 2 in 5 ml of MeOH.…”

mentioning

confidence: 99%