21370-53-6Relevant academic research and scientific papers
A green hunsdiecker reaction of cinnamic acids
Sodre?, Leonardo R.,Esteves, Pierre M.,De Mattos, Marcio C. S.
, p. 212 - 218 (2013/05/08)
Tribromo- and trichloroisocyanuric acids react with cinnamic acids in NaOH/H2O/Et2O at room temperature to produce (E)-2-halostyrenes regioselectively in 25-95percent yield. Mechanism studies using Hammett correlations and DFT (density functional theory) calculations have shown that this reaction has as rate determining step the electrophilic addition of chlorine atom to the double bond.
Widely applicable Pd-catalyzed trans-selective monoalkylation of unactivated 1,1-dichloro-1-alkenes and Pd-catalyzed second substitution for the selective synthesis of E or Z trisubstituted alkenes
Tan, Ze,Negishi, Ei-Ichi
, p. 762 - 765 (2007/10/03)
(Chemical Equation Presented) Double substitution: The first selective and widely applicable method for a step-wise alkylation of 1,1-dichloro-1-alkenes involving a cross-coupling double substitution using Pd-catalysis has been developed. This method provides an efficient and highly selective route for the synthesis of E or Z trisubstituted alkenes. dpephos = bis(o- diphenylphosphanylphenylether).
ROLE OF THE POLYMER BACKBONE ON THE REACTIVITY OF POLYMER-SUPPORTED (DICHLOROIODO)BENZENE
Sket, Boris,Zupan, Marko,Zupet, Pavle
, p. 1603 - 1606 (2007/10/02)
Chlorination of iodinated crosslinked polystyrene with Cl2 gave polyaryliododichloride containing 1.1 mmol of active chlorine per gram of resin, while fluorination of the same iodinated resin with XeF2 gave polyaryliododifluoride, co
Kinetics and Stereochemistry of the Addition of Chlorine to Styrenes
Yates, Keith,Leung, Hei Wun
, p. 1401 - 1406 (2007/10/02)
The chlorination of several ring- and side-chain-substituted styrenes has been studied in anhydrous acetic acid, in both the presence and absence of added perchlorate, chloride, and acetate salts.The reactions give three types of product: the 1,2-dichlorides arising from simple addition, 1-acetoxy-2-chloro compounds from addition followed by solvent incorporation, and β-chlorostyrenes from an addition-elimination process.The reactions are completely regiospecific in the Markownikoff sense, and the addition-elimination products are formed with high stereoselectivity.However, both types of addition product are formed nonstereospecifically.Both the product distribution and stereoselectivity are remarkably insensitive to added perchlorate, chloride, or acetate, and very high concentrations of these salts (ca. 1.0 M) are required to produce any significant change in product composition.These results are explicable in terms of a product-determining intermediate which consists of an intimate ion pair between an open β-chlorobenzyl carbonium ion and a tightly held chloride counterion.However, since (E)- and (Z)-1-phenylpropenes do not give similar product distributions under any conditions used, rotation of the Cα-Cβ bond in the carbonium ion must be highly restricted.The rates of reaction have been studied by a combination of potentiometric and stopped-flow spectrophotometric techiques.The reactions are first order in chlorine and first order in olefin and are generally very fast, with most of the rate constants being in the range 102-105 L mol-1 s-1.The rate constants for the ring-substituted styrenes give a good linear correlation against ?+ with a β value of -3.22.This value is less negative than expected from a comparison with other electrophilic additions and is discussed in terms of an earlier transition state with less charge development at Cα than in the analogous bromination reaction.The activation parameters obtained for two of the styrenes support this hypothesis.There is no direct evidence for chlorine bridging at either the transition state or the intermediate stage.
