Reaction mechanisms of iron(<scp>iii</scp>) catalyzed carbonyl–olefin metatheses in 2,5- and 3,5-hexadienals: significant substituent and aromaticity effects

Chen, Dandan; Zhuang, Danling; Zhao, Yu; Xie, Qiong; Zhu, Jun

doi:10.1039/c9qo01008d

Cited by 18 publications

(11 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was first applied to electronic excited states by Dewar and Zimmerman in the 1960s to explain the formation of four-membered rings in photochemical electrocyclization reactions. These authors proposed that such reactions proceed through aromatic transition structures, which are also known to mediate thermal electrocyclization, − sigmatropic rearrangement, , nonpericyclic ring-closure, , and carbonyl-olefin metathesis reactions. Subsequently, Baird used semiempirical molecular orbital theory calculations to formulate rules for aromaticity and antiaromaticity in the lowest triplet excited state (T 1 ) of cyclic conjugated hydrocarbons.…”

Section: Introductionmentioning

confidence: 99%

Photoinduced Changes in Aromaticity Facilitate Electrocyclization of Dithienylbenzene Switches

et al. 2020

View full text Add to dashboard Cite

The concepts of excited-state aromaticity and antiaromaticity have in recent years with increasing frequency been invoked to rationalize the photochemistry of cyclic conjugated organic compounds, with the long-term goal of using these concepts to improve the reactivities of such compounds toward different photochemical transformations. In this regard, it is of particular interest to assess how the presence of a benzene motif affects photochemical reactivity, as benzene is well-known to completely change its aromatic character in its lowest excited states. Here, we investigate how a benzene motif influences the photoinduced electrocyclization of dithienylethenes, a major class of molecular switches. Specifically, we report on the synthesis of a dithienylbenzene switch where the typical nonaromatic, ethene-like motif bridging the two thienyl units is replaced by a benzene motif, and show that this compound undergoes electrocyclization upon irradiation with UV-light. Furthermore, through a detailed quantum chemical analysis, we demonstrate that the electrocyclization is driven jointly and synergistically by the loss of aromaticity in this motif from the formation of a reactive, antiaromatic excited state during the initial photoexcitation, and by the subsequent relief of this antiaromaticity as the reaction progresses from the Franck–Condon region. Overall, we conclude that photoinduced changes in aromaticity facilitate the electrocyclization of dithienylbenzene switches.

show abstract

Section: Introductionmentioning

confidence: 99%

Photoinduced Changes in Aromaticity Facilitate Electrocyclization of Dithienylbenzene Switches

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The “superelectrophilic” Lewis acid–base complex 481 is now sufficiently activated to undergo the desired carbonyl–olefin ring-closing metathesis reaction via [2 + 2]-cycloaddition to form intermediate oxetane 482 and subsequent retro [2 + 2]-cycloaddition to ultimately give rise to the metathesis products cyclopentene 468 and acetone 27 . Recently, the singly bridged FeCl 3 dimer has been investigated computationally by Zhu and co-workers in their studies of the carbonyl–olefin metathesis reactions to form aromatic species …”

Section: Lewis Acid-catalyzed Carbonyl–olefin Metathesis Reactionsmentioning

confidence: 99%

“…Recently, the singly bridged FeCl 3 dimer has been investigated computationally by Zhu and co-workers in their studies of the carbonyl−olefin metathesis reactions to form aromatic species. 127 During their studies of intramolecular carbonyl-ene reactions of aliphatic ketone 394, Dunãch and co-workers reported evidence of the carbonyl−olefin metathesis product in the investigations of catalytic, intramolecular carbonyl-ene reaction of aliphatic that in addition to the carbonyl-ene product 483 and its dehydrated analog 484, cyclohexene 395 was formed as the carbonyl−olefin metathesis product. 119 In the presence of Bi(OTf) 3 , acting as the Lewis acid catalyst, 394 undergoes the carbonyl-ene reaction to provide cis-and trans-carbonyl-ene products 483, the elimination product 484, and the metathesis product 395 in a combined yield of 32% and a 41:50:5 ratio (Scheme 83).…”

Section: Catalytic Carbonyl−olefin Ring-closing Metathesis Of Aliphat...mentioning

confidence: 99%

Carbonyl–Olefin Metathesis

et al. 2021

View full text Add to dashboard Cite

This Review describes the development of strategies for carbonyl−olefin metathesis reactions relying on stepwise, stoichiometric, or catalytic approaches. A comprehensive overview of currently available methods is provided starting with Paterno−Buchi cycloadditions between carbonyls and alkenes, followed by fragmentation of the resulting oxetanes, metal alkylidene-mediated strategies, [3 + 2]-cycloaddition approaches with strained hydrazines as organocatalysts, Lewis acid-mediated and Lewis acidcatalyzed strategies relying on the formation of intermediate oxetanes, and protocols based on initial carbon−carbon bond formation between carbonyls and alkenes and subsequent Grob-fragmentations. The Review concludes with an overview of applications of these currently available methods for carbonyl−olefin metathesis in complex molecule synthesis. Over the past eight years, the field of carbonyl−olefin metathesis has grown significantly and expanded from stoichiometric reaction protocols to efficient catalytic strategies for ring-closing, ring-opening, and cross carbonyl− olefin metathesis. The aim of this Review is to capture the status quo of the field and is expected to contribute to further advancements in carbonyl−olefin metathesis in the coming years.9396 7.2. Cross Carbonyl−Olefin Metathesis 9396 8. Applications in Natural Product Synthesis 9398 9.

show abstract

“…To expand the scope of Fe III -catalyzed carbonyl-olefin reactions towards 2,5-and 3,5-hexadienals, analog to the Schindler's work (Scheme 19), Zhu and co-workers performed computational investigations to get information on how substitution patterns of those derivative may have beneficial influence on the outcome of the reaction [47]. Scheme 18.…”

Section: Scheme 15 General Equation For the Synthesis Of Polycyclesmentioning

confidence: 99%

Iron-Catalyzed Carbonyl–Alkyne and Carbonyl–Olefin Metathesis Reactions

Grau

Tsogoeva

2020

Catalysts

View full text Add to dashboard Cite

Construction of carbon–carbon bonds is one of the most important tools for the synthesis of complex organic molecules. Among multiple possibilities are the carbonyl–alkyne and carbonyl–olefin metathesis reactions, which are used to form new carbon–carbon bonds between carbonyl derivatives and unsaturated organic compounds. As many different approaches have already been established and offer reliable access to C=C bond formation via carbonyl–alkyne and carbonyl–olefin metathesis, focus is now shifting towards cost efficiency, sustainability and environmentally friendly metal catalysts. Iron, which is earth-abundant and considered as an eco-friendly and inexpensive option in comparison to traditional metal catalysts, fulfils these requirements. Hence, the focus of this review is on recent advances in the iron-catalyzed carbonyl–alkyne, carbonyl–olefin and related C–O/C–O metathesis reactions. The still large research potential for ecologically and economically attractive and sustainable iron-based catalysts is demonstrated.

show abstract

Reaction mechanisms of iron(iii) catalyzed carbonyl–olefin metatheses in 2,5- and 3,5-hexadienals: significant substituent and aromaticity effects

Abstract: Theoretical calculations reveal significant substituent and aromaticity effects on Fe(iii)-catalyzed carbonyl–olefin metatheses of hexadienals.

Cited by 18 publications

References 62 publications

Photoinduced Changes in Aromaticity Facilitate Electrocyclization of Dithienylbenzene Switches

Photoinduced Changes in Aromaticity Facilitate Electrocyclization of Dithienylbenzene Switches

Carbonyl–Olefin Metathesis

Iron-Catalyzed Carbonyl–Alkyne and Carbonyl–Olefin Metathesis Reactions

Contact Info

Product

Resources

About