Total Synthesis of Dictyodendrin A and B

Okano, Kentaro; Fujiwara, Hideto; Noji, Toshiharu; Fukuyama, Tohru; Tokuyama, Hidetoshi

doi:10.1002/ange.201001966

Cited by 28 publications

(14 citation statements)

References 28 publications

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“…We first prepared the corner unit in the form of bromophenylated 9,10‐epoxyanthracene. Benzyne generated from phenyl trifluoromethanesulfonate and magnesium amide [Mg(TMP) 2 ⋅2 LiCl] was adopted for the Diels–Alder reaction with bromophenylated isobenzofuran 1 to afford the corner unit 2 in a good yield (Scheme ) . The corner unit 2 was then subjected to the Ni‐mediated, Yamamoto‐type macrocyclization reaction .…”

Section: Resultsmentioning

confidence: 99%

An Obtuse‐angled Corner Unit for Fluctuating Carbon Nanohoops

Sun

Miyamoto

Sato

et al. 2016

Chemistry An Asian Journal

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The invention of corner units was the key factor that allowed the synthesis of cyclo-para-phenylenes with strained curved π-systems. Despite only a few scarce instances of the development of corner units to date, a variety of structural congeners have been synthesized. These preceding corner units commonly possessed directing angles of ≤90°, which enabled the macrocyclization of multiple units, up to six. In this study, we introduce an obtuse-angled corner unit for the synthesis of cyclo-para-phenylene congeners. The corner unit with oxanorbornadiene possessed a directing angle of 126° and thus allowed for the macrocyclization of larger structures with up to seven units. Reductive aromatization was applicable to complete the cyclo-para-phenylene structures and afforded the congeners with multiple anthracenylene panels. Structural studies with experimental and theoretical methods revealed a fluctuating structure with an intrinsic non-belt shape.

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Section: Resultsmentioning

confidence: 99%

An Obtuse‐angled Corner Unit for Fluctuating Carbon Nanohoops

Sun

Miyamoto

Sato

et al. 2016

Chemistry An Asian Journal

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“…Thec yano group possesses ap seudo-equatorial conformation. Although Cu-mediated amination reactions of aryl triflates are rather rare compared with those of halides, [24,25] ap rocedure (CuI, CsOAc,NMP) modified from that of Fukuyama et al [26] delivers the indoline in 64 %y ield along with 27 %o f recovered 5.N otably,N MP was as uperior solvent to previously reported DMSO [26] (< 20 %y ield) in this case. [21] Thec ompletion of the synthesis relied on aC À Nb ond forming reaction.…”

Section: Angewandte Chemiementioning

confidence: 77%

Asymmetric Total Synthesis of Mycoleptodiscin A

et al. 2015

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The first total synthesis of mycoleptodiscin A, as tructurally unusual indolosesquiterpenoid possessing an ortho-benzoquinone motif,h as been accomplished. As ulfone alkylation coupled two readily available fragments to give an aryl triene intermediate.T he tetracyclic core of the molecule was assembled through ah ighly enantioselective iridiumcatalyzedpolyene cyclization. The benzylic homologation was achieved by ac ationic cyanation. The indole motif was constructed via ac opper-mediated intramolecular C À Nb ond formation at alate stage.

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“…Yamagushi et al also applied the strategy of a 6π‐electrocyclization from pentasubstituted pyrrole derivative 126 for the construction of cycle B (Scheme ) . After treatment of 126 with an excess of LDA, enolate 127 cyclized to give pyrrolocarbazole 128 that could be used as intermediate for the synthesis of dictyodendrin A in 6 steps via compound 138 , (see below, Scheme ).…”

Section: Synthesis and Biological Activities Of 36‐dihydropyrrolomentioning

confidence: 99%

“…Tokuyama's group proposed an approach to dictyodendrins A–E based on the construction of cycle C of the tetracyclic core , . The strategy was based on the thermal formation of a nitrene intermediate from azides 135a – e prepared from the pinacolboronate synthesized from bromo intermediates 134a – e (Scheme ).…”

Section: Synthesis and Biological Activities Of 36‐dihydropyrrolomentioning

confidence: 99%