The Alkynyl Moiety as a Donor for Donor–Acceptor Cyclopropanes

Haubenreisser, Stefan; Hensenne, Peter; Schröder, Sebastian; Niggemann, Meike

doi:10.1021/ol400809n

Cited by 69 publications

(17 citation statements)

References 35 publications

(6 reference statements)

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“…The formation of 2,5‐ trans ‐derivatives (with respect to the donor) 43 e was also observed in the Ca II ‐catalyzed cycloadditions reported by Niggemann and co‐workers, in which an alkyne acts as the donor. This result was dependent on neither the steric demand nor on the electronic influence of the residue R in the geminal position to the donor (Table 4, entry 7) 41. Similar results could be obtained when using a Ru II catalyst.…”

Section: Cycloadditionssupporting

confidence: 72%

A New Golden Age for Donor–Acceptor Cyclopropanes

2014

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The effective use of ring strain has been applied to considerable advantage for the construction of complex systems. The focus here is directed towards cyclopropanes as building blocks for organic synthesis. Although thermodynamics should take the side of synthetic chemists, only a specific substitution pattern at the cyclopropane ring allows for particularly mild, efficient, and selective transformations. The required decrease in the activation barrier is achieved by the combined effects of vicinal electron-donating and electron-accepting moieties. This Review highlights the appropriate tools for successfully employing donor-acceptor cyclopropanes in ring-opening reactions, cycloadditions, and rearrangements.

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Section: Cycloadditionssupporting

confidence: 72%

A New Golden Age for Donor–Acceptor Cyclopropanes

2014

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“…Elemental analyses were either performed at London Metropolitan University or at Chalmers University. Compounds 17 , 18 , and 21 were made by their respective literature methods.…”

Section: Methodsmentioning

confidence: 99%

Triazole‐Functionalized Norbornadiene‐Quadricyclane Photoswitches for Solar Energy Storage

2018

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Herein work on 2,3‐substituted norbornadiene‐quadricyclane molecular photoswitches designed for solar energy storage purposes is presented. A series of six new systems bearing 1,4‐ or 1,5‐alkyl triazoles as the acceptor unit combined with various aryl donor groups, as well as four functional intermediates, were synthesized and fully characterized. The new photoswitches were evaluated by measuring optical absorption profiles, activation energies for the thermal conversion of quadricyclanes to norbornadienes, as well as the storage energy densities. These triazoles featured a molar energy storage of 81.2–101 kJ mol–1corresponding to energy densities of 215–267 kJ kg–1. The optical absorption profiles exhibited absorption onsets up to 382 nm and a study of the thermally activated conversion from high‐energy quadricyclanes to norbornadienes revealed energy storage half lives of up to 402 days at 25 °C. The modular nature of the “click chemistry” synthesis concept used herein enables access to a large range of compounds with tailored properties such as solubility, thermal half‐life, and solar spectrum match.

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“…dehydes and D-A cyclopropanes to yield tetrahydrofurans with a good diastereoselectivity under mild conditions within a few minutes (Scheme 22). 42 The ring opening is likely to be induced by the activation of the acceptor moiety (malonate) by Ca(II) to generate a zwitterionic intermediate 94, in which the alkyne plays the role of donor. Then, 94 undergoes a [3+2] cycloaddition with the aldehyde.…”

Section: Short Review Syn Thesismentioning

confidence: 99%

Carbon–Carbon and Carbon–Heteroatom Bond-Forming Transformations Catalyzed by Calcium(II) Triflimide

Lebœuf

Gandon

2017

Synthesis

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The aim of this short review is to highlight the interest of using Ca(NTf 2) 2 as catalyst in CC and C-X bond-forming reactions. The ability of this complex to activate alcohols, alkenes, ketones, and cyclopropanes towards nucleophilic additions and other chemical processes is shown though a set of selected examples, which illustrate the substrate scope and the synthetic applications offered by this 'green' calcium salt. 1 Introduction 2 Synthetic Applications 3 Conclusion Key words ammonium salt, calcium, CC bond-forming reactions, CO bond functionalization, C-X bond-forming reactions, homogeneous catalysis, weakly coordinating anion After graduating from ESPCI, David Leboeuf (left) pursued his Ph.D. at the University Pierre et Marie Curie (UPMC-Paris 6) with Prof. Max Malacria until 2009 (on Co-, Rh-, and Au-catalyzed cyclizations). After 2.5 years of postdoctoral research at the University of Rochester with Prof. Alison Frontier (on Cu-mediated Nazarov cyclizations) and 1 year at the Institute of Chemical Research of Catalonia (ICIQ) with Prof. Antonio Echavarren (on the development of new Au catalysts), he was appointed by the CNRS as Chargé de Recherche in 2013 at the University Paris-Sud, where he started research program dedicated to calcium catalysis and supramolecular chemistry. Vincent Gandon (right) received his Ph.D. in 2002 from the University of Reims Champagne Ardenne (group of Prof. Jan Szymoniak). After a postdoctoral stay at the University of California, Riverside, in the group of Prof. Guy Bertrand, he joined the faculty of the Pierre et Marie Curie University in Paris in 2003 and worked as Assistant Professor in the laboratory of Prof. Max Malacria. In 2009, he was appointed full Professor at the Paris-Sud University with a research excellence chair. Since 2012, Vincent has been a junior member of the Institut Universitaire de France (IUF), and since 2014, a junior distinguished member of the French Chemical Society (SCF). His research interests are focused on homogeneous catalysis using cobalt, gold, calcium, and gallium complexes, both from an experimental and a theoretical point of view.

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The Alkynyl Moiety as a Donor for Donor–Acceptor Cyclopropanes

Cited by 69 publications

References 35 publications

A New Golden Age for Donor–Acceptor Cyclopropanes

A New Golden Age for Donor–Acceptor Cyclopropanes

Triazole‐Functionalized Norbornadiene‐Quadricyclane Photoswitches for Solar Energy Storage

Carbon–Carbon and Carbon–Heteroatom Bond-Forming Transformations Catalyzed by Calcium(II) Triflimide

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