Preparation and Some Reactions of 2-(1,3-Butadienyl)magnesium Chloride

Aufdermarsh, Carl A.

doi:10.1021/jo01030a084

Cited by 40 publications

(11 citation statements)

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“…Unfortunately, their reactions with electrophiles suffer from competing reaction of the metalloallenes, which are in equilibrium with the diene [Eq. (20)] 31 To circumvent this problem, a 1‐bromo‐1‐lithiocyclopropane was utilized as a masked diene for the synthesis of an advanced taxusin intermediate.…”

Section: Development Of the Scope Of The Reactionmentioning

confidence: 99%

The Type 2 Intramolecular Diels-Alder Reaction: Synthesis and Chemistry of Bridgehead Alkenes

Bear

Sparks

Shea

2001

Angew. Chem. Int. Ed.

190

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Anti‐Bredt alkenes, bicyclic molecules that contain a bridgehead double bond, were for many years regarded as chemical curiosities. The type 2 intramolecular Diels–Alder (IMDA) reaction provides a one‐step entry into this fascinating class of molecules. The reaction has made available numerous anti‐Bredt alkenes for structural and chemical studies. X‐ray crystallography has revealed the magnitude of the deformations associated with the bridgehead double bond, and rate studies of reactions of bridgehead alkenes have allowed quantification of the kinetic consequences of the torsional distortions. More recently, the type 2 intramolecular Diels–Alder reaction and the resulting anti‐Bredt alkenes have found application in organic synthesis. The constraints resulting from the connectivity in the Diels–Alder precursor creates a strong regio‐ and stereochemical bias in the cycloaddition step. The end result of this bias is the stereoselective synthesis of highly substituted six‐membered rings. The reaction also achieves a facile synthesis of seven‐ and eight‐membered rings in a single step from acyclic precursors. The utility of this reaction has been verified in recent applications of the type 2 IMDA reaction as a key step in the total synthesis of complex natural products.

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Section: Development Of the Scope Of The Reactionmentioning

confidence: 99%

The Type 2 Intramolecular Diels-Alder Reaction: Synthesis and Chemistry of Bridgehead Alkenes

Bear

Sparks

Shea

2001

Angew. Chem. Int. Ed.

190

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“…Cationic polymerization with Lewis acids yields resinous homopolymers containing cyclic structures and reduced unsaturation (40)(41)(42). Polymerization with triethylaluminum and titanium tetrachloride gave a product thought to have a cyclic ladder structure (43).…”

Section: Other Modes Of Polymerizations Popcorn Polymerizationmentioning

confidence: 99%

Polychloroprene

Glenn¹

2004

Kirk-Othmer Encyclopedia of Chemical Technology

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The active center of the chain transfer agent reacts with the growing chain to stop further chain propagation. A new free radical, A, is formed from the Vol. 0 POLYCHLOROPRENE POLYCHLOROPRENE Vol. 0Chloroprene-Sulfur Copolymerization. The high reactivities of chloroprene and dichlorobutadiene permit copolymerization with sulfur to yield toluene-insoluble and partially gelled copolymers of high molecular weight. Gelled polymers are highly crosslinked polymers that are insoluble in toluene.In solution or aqueous emulsion polymerization, a growing polychloroprene radical reacts with rhombic (nonpolymeric) sulfur (24) or suitable sulfur donors such as 1,2,3,4-tetrasulfocyclohexane (25) or polysulfides (26) to yield a copolymer. Reaction with elemental sulfur involves cleavage of the eight-membered sulfurGraft Polymerization. Graft polymerization is related to block copolymerization. A block copolymer contains long sequences of two monomers (ie, AAA monomer blocks followed by BBB monomer blocks) along the copolymer chain. Graft copolymers consist of long chains of one monomer with occasional branches consisting of long chains of a second (grafted) comonomer. The branched points are normally formed by allylic atom (typically hydrogen) abstraction by free-radical initiators (eg, peroxides) to yield a resonance-stabilized free radical. The free radical initiates the addition polymerization of a second monomer beginning at the locus of the free radical. Generally grafting is performed to significantly modify polymer properties. In the production of emulsion-polymerized acrylonitrilebutadiene-styrene tripolymer, styrene and acrylonitrile are grafted onto rubbery polybutadiene to improve compatibility between the thermoplastic and rubber matrix used in impact modification (12). Methyl acrylate, acrylonitrile, alkyl methacrylates (eg, methyl, octyl, lauryl), fumaronitrile, methacrylic acid, and dichlorobutadiene have been employed in solution and emulsion graft polymerization with polychloroprene. Generally, solvent resistance, heat resistance, and Vol. 0 POLYCHLOROPRENE 7 POLYCHLOROPRENE Vol. 0 POLYCHLOROPRENE Vol. 0 POLYCHLOROPRENE Vol. 0 9.5. Latex Applications. A good way to remember the applications for latex is to follow the first six letters of the alphabet. A ¼ adhesives, B ¼ binders, C ¼ coatings, D ¼ dipped Goods, E ¼ elasticizers, and F ¼ foam. Vol. 0 POLYCHLOROPRENE 25

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“…Bei ihrer Reaktion mit Elektrophilen konkurrieren jedoch leider die Metalloallene, die mit dem Dien im Gleichgewicht stehen [Gl. (20)] 31 Um dieses Problem zu umgehen, nutzten wir ein 1‐Brom‐1‐lithiocyclopropan als maskiertes Dien zur Synthese einer der letzten Zwischenstufen auf dem Weg zum Taxusin.…”

Section: Abklären Des Synthesepotentials Der Reaktionunclassified

Intramolekulare Diels-Alder-Reaktion vom Typ 2: Synthese und Chemie von Brückenkopf-Alkenen

2001

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Sparks wurde 1972 geboren und wuchs in Stockbridge, Massachusetts, auf. Er erhielt seinen BSc 1995 am Rensselaer Polytechnic Institute, wobei er ein einjähriges Forschungspraktikum bei Burroughs Wellcome in der Abteilung für Organische Chemie absolvierte. Nach einem Jahr als Forschungslaborant bei Albany Molecular Research begann er seine Doktorarbeit an der UCI unter Anleitung von Professor Kenneth J. Shea. Zu seinen Forschungsinteressen gehört die Entwicklung von Hetero-Diels-Alder-Typ-2-Reaktionen und die Naturstoffsynthese. Kenneth J. Shea wurde in Queens im Staat New York geboren. Er erhielt den BSc und den MSc in Chemie von der University of Toledo. Seine Doktorarbeit führte er auf dem Gebiet der Physikalischen Organischen Chemie an der Pennsylvania State University durch. Nach einem Postdoc-Aufenthalt am California Institute of Technology wurde er 1974 Professor an der University of California in Irvine. Seine Forschungsinteressen sind auf präparative und mechanistische Organische Chemie, auf Polymerchemie und auf Materialforschung gerichtet. B. R. Bear K. J. Shea S. M. Sparks Schema 1. Vorschlag für eine Reaktionskaskade, die von 1 zu 3 führt.

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Preparation and Some Reactions of 2-(1,3-Butadienyl)magnesium Chloride

Cited by 40 publications

References 0 publications

The Type 2 Intramolecular Diels-Alder Reaction: Synthesis and Chemistry of Bridgehead Alkenes

The Type 2 Intramolecular Diels-Alder Reaction: Synthesis and Chemistry of Bridgehead Alkenes

Polychloroprene

Intramolekulare Diels-Alder-Reaktion vom Typ 2: Synthese und Chemie von Brückenkopf-Alkenen

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