Multiple reactivities of dithranol towards 1-alkynyl Fischer carbene complexes (CO)5MC(OEt)CCPh (M=Cr, W) – Efficient chemical synthesis of aromatic polyketides

Luo, Ning; Yu, Zhengkun

doi:10.1016/j.jorganchem.2009.05.029

Cited by 5 publications

(4 citation statements)

References 25 publications

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“…The reactivity is clearly determined by the reactive phenolic moieties in 5 and not by the structure of the starting carbene complexes, which behave as activated alkynes regardless of the nature of the M(CO) 5 fragment. [14] No Diels-Alder-type adducts were observed in these reactions. In this article we report an experimental and theoretical study of the reactivity of Cr 0 and W 0 alkynyl alkoxy Fischer carbene complexes (highly activated alkynes) with bidentate nucleophiles (anthrone and 3-hydroxy-2-pyrone) that can also react as dienes.…”

Section: Introductionmentioning

confidence: 87%

“…Early attempts made with highly reactive dithranol (1,8‐dihydroxyanthrone, 5 ) and dimethyl acetylenedicarboxylate showed that no reaction occurred, even in acetic acid at reflux, although the Diels–Alder cycloadduct was finally obtained with an excess of LiOMe/THF . In clear contrast, Luo and Yu reported that the reaction of 5 with group 6 Cr 0 or W 0 alkynyl (Fischer) carbenes 6 proportioned a complex solvent‐dependent mixture of products 7 – 10 , derived from a combination of Michael additions, electrophilic aromatic substitutions and O ‐directed cyclizations (Scheme ). The reactivity is clearly determined by the reactive phenolic moieties in 5 and not by the structure of the starting carbene complexes, which behave as activated alkynes regardless of the nature of the M(CO) 5 fragment .…”

Section: Introductionmentioning

confidence: 99%

“…In clear contrast, Luo and Yu reported that the reaction of 5 with group 6 Cr 0 or W 0 alkynyl (Fischer) carbenes 6 proportioned a complex solvent‐dependent mixture of products 7 – 10 , derived from a combination of Michael additions, electrophilic aromatic substitutions and O ‐directed cyclizations (Scheme ). The reactivity is clearly determined by the reactive phenolic moieties in 5 and not by the structure of the starting carbene complexes, which behave as activated alkynes regardless of the nature of the M(CO) 5 fragment . No Diels–Alder‐type adducts were observed in these reactions.…”

Section: Introductionmentioning

confidence: 99%

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Understanding the Reactivity of Group 6 Metal (M = Cr, W) Alkynyl Fischer Carbene Complexes with Multi‐Reactive Masked Dienes

et al. 2018

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Group 6 alkynyl Fischer carbene complexes behave as electrophiles with highly reactive masked dienes such as anthrone and 3‐hydroxy‐2‐pyrone, which also can react as bidentate nucleophiles. Both Cr0 and W0 alkynyl carbene complexes require tertiary amines to promote the formation of 1,4‐C‐addition products, but a marked dependence of the reactivity on the metal was observed. Although W0 complexes form exclusively the 1,4‐C‐adducts in the presence of a catalytic amount of base, Cr0 complexes lead to new anthrone‐derived bis‐carbene complexes, obtained by a sequential 1,4‐C‐ and 1,4‐O‐addition process with high diastereoselectivity and only in the presence of an excess of base. DFT computational studies show that the gap between the LUMO of the complex and the HOMO of the anthrone determines the differences in reactivity and that the stability of the intermediate metal allenyls formed after the initial 1,4‐addition is decisive for the outcome of the reaction.

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Section: Introductionmentioning

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Understanding the Reactivity of Group 6 Metal (M = Cr, W) Alkynyl Fischer Carbene Complexes with Multi‐Reactive Masked Dienes

et al. 2018

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“…Initially, when they attempted to prepare different kinds of α,β-unsaturated Fischer carbene complexes, the reaction of hydroxybenzaldehyde 12 with methyl ethoxycarbene complex 11 was found to accidentally yield the benzopyranylidene complex 13 in 82% yield in the presence of Et 3 N (eq. (3)) [27][28][29][30][31][32][33][34][35][36][37][38][39].…”

Section: [3+3] Cyclizationmentioning

confidence: 99%

Advances in the synthesis and reactivity of 2-pyranylidene carbene complexes

et al. 2010

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Pyranylidene carbene complexes bearing a pyran ring carbene ligand represent a unique kind of organometallic species due to their special structures and reactivity. In this review, we present a comprehensive summary on the synthesis and reactivity of pyranylidene carbene complexes during the past four decades. 2-pyranylidene carbene complexes, synthesis, reactivity Citation:Wang Q F, Zhang W X, Lin C, et al. Advances in the synthesis and reactivity of 2-pyranylidene carbene complexes.Fischer-type carbene complexes are among the most important organometallic compounds, and these have experienced a considerable surge in recent times because of their widespread application in synthetic organic chemistry since the first carbene complex was reported by Fischer and coworkers in 1964 [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. During the course of the development of Fischer-type carbene complexes, unsaturated Fischer carbene complexes, in which unsaturated substituents are attached to the carbene carbon center, occupy an important status owing to their good reactivity in Michael-type reactions, cycloaddition reactions, transmetalation reactions. The strong electron-withdrawing property of the pentacarbonyl metal moiety and the electron-deficient property of the β-position carbon resulting from electron-transfer from the carbene center play a cooperative effect on the versatile reactivity of unsaturated Fischer carbene complexes [2-18]. 2-Pyranylidene metal carbene complexes bearing a pyran ring carbene ligand are a special kind of unsaturated Fischer carbene complex, that has received much less attention probably because of their limitation of the synthetic methodology. Recently, some important progress has been made *Corresponding author (email: zfxi@pku.edu.cn) by the chemical community. Here we give a comprehensive review of the synthesis and reactivity of the 2-pyranylidene metal carbene complex during the past four decades.

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The chemistry of the carbon–transition metal double and triple bond: Annual survey covering the year 2009

Herndon

2011

Coordination Chemistry Reviews

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Multiple reactivities of dithranol towards 1-alkynyl Fischer carbene complexes (CO)5MC(OEt)CCPh (M=Cr, W) – Efficient chemical synthesis of aromatic polyketides

Cited by 5 publications

References 25 publications

Understanding the Reactivity of Group 6 Metal (M = Cr, W) Alkynyl Fischer Carbene Complexes with Multi‐Reactive Masked Dienes

Understanding the Reactivity of Group 6 Metal (M = Cr, W) Alkynyl Fischer Carbene Complexes with Multi‐Reactive Masked Dienes

Advances in the synthesis and reactivity of 2-pyranylidene carbene complexes

The chemistry of the carbon–transition metal double and triple bond: Annual survey covering the year 2009

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