- Sulfated polyborate-H2O assisted tunable activation of N-iodosuccinimide for expeditious mono and diiodination of arenes
-
Owing to both Lewis and Bronsted acid active sites on sulfated polyborate under homogenous conditions, we were keen on developing iodination protocol of arenes that can meet the requirement of regioselectivity and higher yield. The sulfated polyborate activates N-iodosuccinimide for mono iodination of highly activated substrates viz. phenols, anilines under anhydrous condition. Water tunes sulfated polyborate to generate more Bronsted acid sites resulting in rapid activation of NIS for diiodination. The protocol was equally applicable to diiodination of 4-hydroxyphenylacetic acid to synthesize 4-hydroxy-3,5-diiodophenylacetic acid, an intermediate of tiratricol, a thyroid treatment drug. This protocol was further integrated via one-pot sequential iodination and Sonogashira coupling to synthesize aryl acetylenes, building blocks for the synthesis of a variety of specialty chemicals, API, and natural products.
- Misal, Balu,Palav, Amey,Ganwir, Prerna,Chaturbhuj, Ganesh
-
supporting information
(2021/05/26)
-
- NCBSI/KI: A Reagent System for Iodination of Aromatics through in Situ Generation of I-Cl
-
In situ iodine monochloride (I-Cl) generation followed by iodination of aromatics using NCBSI/KI system has been developed. The NCBSI reagent requires no activation due to longer bond length, lower bond dissociation energy, and higher absolute charge density on nitrogen. The system is adequate for mono- and diiodination of a wide range of moderate to highly activated arenes with good yield and purity. Moreover, the precursor N-(benzenesulfonyl)benzenesulfonamide can be recovered and transformed to NCBSI, making the protocol eco-friendly and cost-effective.
- Palav, Amey,Misal, Balu,Chaturbhuj, Ganesh
-
p. 12467 - 12474
(2021/08/24)
-
- Improving the reactivity of phenylacetylene macrocycles toward topochemical polymerization by side chains modification
-
The synthesis and self-assembly of two new phenylacetylene macrocycle (PAM) organogelators were performed. Polar 2-hydroxyethoxy side chains were incorporated in the inner part of the macrocycles to modify the assembly mode in the gel state. With this modification, it was possible to increase the reactivity of the macrocycles in the xerogel state to form polydiacetylenes (PDAs), leading to a significant enhancement of the polymerization yields. The organogels and the PDAs were characterized using Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM).
- Rondeau-Gagne, Simon,Neabo, Jules Romeo,Daigle, Maxime,Cantin, Katy,Morin, Jean-Francois
-
supporting information
p. 1613 - 1619
(2014/08/05)
-
- PROCESS FOR PRODUCTION OF PHENOL DERIVATIVES SUBSTITUTED WITH IODINE AT ORTHO POSITION
-
A process in which a phenol derivative is iodinated to produce a 2-iodophenol or 2,6-diiodophenol derivative substituted with iodine at an ortho position thereof is provided, which does not require any step of recovery of iodine but can produce it at low cost, in high yield and with high quality. A phenol derivative is mixed with a pyridine and hydrogen peroxide or iodic acid as an oxidizing agent, and reacted with molecular iodine. As a result, iodination can be performed very efficiently with iodine in an amount close to the theoretical amount relative to the phenol derivative, and the 2-iodophenol or 2,6-diiodophenol derivative can be obtained in high yield and with high quality.
- -
-
Page/Page column 6
(2010/07/06)
-
- Structure effect relationships of amiodarone analogues on the inhibition of thyroxine deiodination
-
Objectives: Amiodarone (AMI) has proven to be a potent anti-arrhythmic compound. Due to the structural similarity between AMI and thyroid hormone, it is possible that the drug could inhibit the activity of the 5'-thyroxine- deiodinase. Methods: AMI analogues resulting from (1) dealkylation, (2) deiodination and (3) deamination were synthesised and used as inhibitors in an in vitro biotransformation reaction of thyroxine (T4) to 3,3',5'- triiodothyronine (T3). Using high-performance liquid chromatography and ultraviolet detection for quantifying T3, it was found that the 5'-T4 deiodinase type I was involved in the reaction. On separate occasions, AMI or an AMI analogue was added to the reaction as an inhibitor. Results: All studied AMI analogues inhibited 5'-T4 deiodination competitively (K(i) value range 25-360 μM). In the concentration range of 1-1000 μM, AMI and its N- desethylated, deiodinated analogues inhibited 5'-T4 deiodination very weakly. AMI analogues with a hydroxyl group at the 4-position were strong inhibitors. Moreover, diiodo-AMI analogues inhibited 5'-T4 deiodination more strongly than their corresponding monoiodo- or deiodinated derivatives. Conclusion: It is likely that the degraded products of AMI could be responsible for thyroid dysfunction toxicosis in AMI therapy.
- Ha,Stieger,Grassi,Altorfer,Follath
-
p. 807 - 814
(2007/10/03)
-