84211-75-6Relevant academic research and scientific papers
A Highly Efficient Copper-Mediated Radioiodination Approach Using Aryl Boronic Acids
Zhang, Pu,Zhuang, Rongqiang,Guo, Zhide,Su, Xinhui,Chen, Xiaoyuan,Zhang, Xianzhong
, p. 16783 - 16786 (2016/11/17)
A convenient and quantitative radioiodination method by copper-mediated cross-coupling of aryl boronic acids was developed. The mild labeling conditions, ready availability of the boronic acid substrate, simple operation, broad functional group tolerance and excellent radiochemical yield (RCY) make this a practical strategy for radioiodine labeling without further purification.
Direct n.c.a. electrophilic radioiodination of deactivated arenes with N-chlorosuccinimide
Mennicke,Holschbach,Coenen
, p. 721 - 737 (2007/10/03)
An efficient method for the direct electrophilic no-carrier-added (n.c.a.) radioiodination of deactivated arenes has been developed using N-chlorosuccinimide (NCS)/radioiodide in trifluoromethanesulfonic acid (triflic acid). Optimization of the one pot labelling procedure using chlorobenzene as a model substrate resulted in a radiochemical yield of 75% within 15 min at room temperature. Drying of the aqueous radioiodide solution prior to radiolabelling was not required. Radioiodination of weakly activated and deactivated monosubstituted benzene derivatives gave rise to radiochemical yields of about 80% with an electrophilic substitution pattern. Strongly deactivated aromatic compounds were radioiodinated with high radiochemical yields of about 70% exclusively in their meta-position using a reaction temperature of 75°C and a reaction time of 1 h. With regard to the reaction mechanism, in situ formed radioiodo(I) trifluoromethanesulfonate (triflyl [131I]hypoiodite) is discussed as electrophilic reagent.
No-carrier-added Radiobromination and Radioiodination of Aromatic Rings using In Situ Generated Peracetic Acid
Moerlein, Stephen M.,Beyer, Werner,Stoecklin, Gerhard
, p. 779 - 786 (2007/10/02)
Peracetic acid generated in situ from aqueous hydrogen peroxide and glacial acetic acid was examined as an oxidizing agent for electrophilic aromatic bromination and iodination without chlorinated side products.No-carrier-added (n.c.a.) 77Br and 131I were used with simple organic aromatic compounds or aryltrimethyl-tin, -germanium, and -silicon organometallic compounds to identify reaction parameters which influence this electrophilic halogenation method.N.c.a. aromatic halogenodeprotonation using peracetic acid was relatively slow and resulted in high labelling yields only with aromatic rings that were activated toward electrophilic substitution.By contrast, high radiochemical yields were rapidly obtained via iododestannylation of aromatic rings regardless of their degree of electronic activation.Useful labelling yields were also achieved using bromodestannylation reactions with aromatic rings deactivated toward electrophiles, but optimum yields with activated systems required the use of germylated arenes as substrates.The practical aspects of aromatic halogenodemetallation and halogenodeprotonation as n.c.a. electrophilic halogenation techniques with in situ generated peracetic acid are outlined.
Regiospecific No-Carrier-Added Radiobromination and Radioiodination of Arylmethyl Group IVb Organometallics
Moerlein, Stephen M.,Coenen, Heinz H.
, p. 1941 - 1948 (2007/10/02)
A series of para-substituted aryltrimethyl-silicon, -germanium, and -tin compounds were treated at room temperature with no-carrier-added (n.c.a.) 77Br and 131I to compare their utility as substrates for regiospecific aromatic halogenation.Dichloramine-T was used as an in situ oxidant in acidic, polar, or non-polar reaction solvents.N.c.a. aromatic halodemetallation was regiospecific for all substrates, radiochemical yields were generally higher for 131I than 77Br, and halogenation yields increased as Si Ge Sn.Arguments are presented for a substitution mechanism involving a ?-complex intermediate with bond formation as the yield-determinig step.Although high yields were obtained for the n.c.a. aromatic halogenodestannylations irrespective of aromatic substituent or solvent, significant chlorination occured as a side-reaction.N.c.a. aromatic halogenodegermylation produced high radiochemical yields with insignificant chlorination, but the radiohalogenation yields were sensitive to ring deactivation and solvent effects.N.c.a. aromatic halogenodesilylation gave high yields only in activated aromatic systems.The relative benefits of each demetallation reaction for regiospecific n.c.a. radiolabelling or preparative halogenation of aromatic rings are outlined.
