Related Experiment Video
Updated: Aug 20, 2026

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of Phosphorus(I)
Published on: November 22, 2016
Synthesis and structure of nongeminally substituted cyclic phosphazenes with haloalkyl and thioester functional
June-Ho Jung1, Srinagesh K Potluri, Hongming Zhang
1Department of Chemistry, Southern Methodist University, Dallas, Texas 75275-0314.
Abstract:
Nongeminally substituted cyclic phosphazenes with various haloalkyl substituents were prepared using deprotonation-substitution reactions at the methyl groups of the cis isomers of nongeminally substituted cis-[Me(Ph)P=N]3, 2. Treatment of 2 with n-BuLi followed by reaction with organic halogenated reagents (RX=C2Cl6, BrC(O)CMe2Br, and ICH2COOEt) at low temperature afforded the various cyclic derivatives cis-[(XCH2)(Ph)PN]3 (3, X=Cl, 4, Br, and 5, I). The mono- and dibromoalkyl derivatives, cis-[Ph3(BrCH2)Me2P3N3], 6, and [Ph3(BrCH2)2MeP3N3], 7, were also isolated along with 4 when the electrophile was dibromoethane. Reaction of cis-[Ph(BrCH2)PN]3, 4, with KSC(O)Me gave cis-[Ph(MeC(O)SCH2)PN]3, 8. The structures of all the cis cyclic phosphazenes were determined by NMR spectroscopy and X-ray diffraction. All retained the basketlike shape with the hydrophobic phenyl groups opposite the haloalkyl groups on the P3N3 ring. Thermal analysis of the new cyclic trimers indicates that ring-opening polymerization does not occur. The melting points and the thermal stabilities of haloalkyl cyclophosphazenes were higher than those of the parent compound 2.
Related Concept Videos
Electrophilic Addition to Alkynes: Halogenation
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
Preparation and Reactions of Sulfides
Alkyl Halides
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction
α-Halogenation of Carboxylic Acid Derivatives: Overview
Aldehydes and Ketones to Alkenes: Wittig Reaction Mechanism
The reaction begins with the nucleophilic addition between a phosphorus ylide and the carbonyl compound. Due to its carbanionic character, phosphorus ylide acts as a strong nucleophile and attacks the electrophilic carbonyl group. This generates a charge-separated dipolar intermediate called betaine. The negatively charged oxygen atom and...
