Low molecular weight MPEG-assisted organic synthesis

Abstract

A toolkit of low molecular weight MPEG-supported coupling agents ((M)IIDQ, (M)EDCI), reagents for the Mitsunobu reaction ((M)DEAD, (M)TPP), an alternative to diazomethane, and scavengers can be used in the solution-phase synthesis of amides, esters and ureas and are easily removed after use by solid-phase extraction (MSPE) using normal silica.

Towards the Discrimination of Carboxylates by Hydrogen‐Bond Donor Anion Receptors

“…Compound 24 was prepared from compound 22 coupled with 1‐pyrenebutyric acid by using EDC ⋅ HCl, HOBt and DMAP and compound 25 was prepared from compound 22 coupled with 1‐naphthyl isocyanate in acetonitrile. The following receptors were synthesised as described in literature: 26 ,31 27 ,32 28 ,33 29 ,16 30 ,17 31 12 and 32 – 47 14. 15…”

Composition‐dependent sol‐gel transition of amphiphilic blend of PEG with hydrophobic gallamide components

“…PEG mono‐amine was basically synthesized as described by Gussin et al . and Figlus et al . Then the diblock‐type PEG1 amphiphile [Figure (a)] was synthesized by the coupling of 4‐methoxy‐3,5‐ bis (tetradecoxy)benzoic acid with the PEG mono‐amine, described by Figlus et al .…”

Nickel‐Mediated Radioiodination of Aryl and Heteroaryl Bromides: Rapid Synthesis of Tracers for SPECT Imaging

“…This was achieved with a short five-step synthesis of 5-[ 123 I]-A85380, the SPECT tracer used for imaging nAChRs (Scheme 3). [21] In the first example of the use of this technology for the preparation of an ether, the Mitsunobu reaction of alcohol 4 with 5bromo-3-pyridinol 5 in the presence of M DEAD gave the coupled product 6 in 82 % yield. Under standard conditions, the amino group of commercially available (2S)-2-azetidinecarboxylic acid (3) was protected with an N-Boc group, followed by chemoselective reduction of the carboxylic acid with borane.…”

“…[8] In this study, this obstacle was overcome using a low-molecular-weight MPEG-supported version of diethyl azodicarboxylate ( M DEAD; reported by Hartley and co-workers), which can be removed at the end of the reaction by solid-phase extraction with silica gel. [21] In the first example of the use of this technology for the preparation of an ether, the Mitsunobu reaction of alcohol 4 with 5bromo-3-pyridinol 5 in the presence of M DEAD gave the coupled product 6 in 82 % yield. The key radioiodination reaction was then performed under our optimized conditions using [ 123 I]-NaI (74 MBq, 237.4 Ci mmol À1 ).…”