Potting compounds commercially available

A new chiral benzothiazine ligand 205 was synthesized by Harmata and co-workers <06JOC3650>. It could be converted into a chiral molecular receptor 207 in a simple way. This chiral species 207 could be used as a new class of chiral molecular tweezers. The synthesis of 205 commenced with the protection of the commercially available compound 202, which was then coupled with f7tj-sulfoximinc 77b using the one-pot, one-operation procedure <99AG(E)2419> affording enantiomerically pure benzothiazine 204. This was followed by deprotection to produce benzothiazine 205 in good yield. 

Catalytic multicomponent synthesis of highly substituted pyrroles has been described. A one-pot reaction uses DBU with the commercially available thiazolium salt 513 to produce the necessary nucleophilic zwitterionic catalyst in situ, which promotes a conjugate addition of acylsilanes (sila-Stetter) and unsaturated ketones to generate 1,4-dicarbonyl compounds in situ. Subsequent addition of various amines promotes a Paal-Knorr reaction, affording the desired polysubstituted pyrrole compounds in a one-pot process in moderate to high yields (Scheme 129) <2004OL2465>. Microwave heating dramatically reduced the reaction time (from 16 h to 30 min), but offered no improvement in yields. 

The tetraacetylenic compound (-)-minquartynoic acid was synthesized in the laboratory of B.W. Gung from commercially available azelaic acid monomethyl ester using a one-pot three-component Cadiot-Chodkiewitz reaction as the key step. This natural product shows strong anti-cancer and anti-HIV activity. One of the alkyne components was prepared using the modified Seyferth-Gilbert homologation. 

The first report of the use of cellulose beads as support for microwave-assisted SPOS was published in 2003 and described the generation of a library of pyrazoles and isoxazoles [49]. The synthesis was performed using commercially available amino cellulose (Perloza VT-100) containing aminoaryl ethyl sulfone groups in flexible chains (Scheme 16.27). Initially, the solid support was treated with excess formyl imidazole and the corresponding yS-keto compounds to generate cellulose-bound enaminones in a one-pot Bredereck-type condensation. The reaction was catalyzed by (+)-camphor-10-sulfonic acid (CSA) and performed under microwave-irradiation conditions in an open vessel to enable the methanol formed to be removed from the reaction equilibrium [49]. 

Chen et al. (2007) demonstrated a very simple, efficient, and practical method for the synthesis of DHPMs and thioderivatives through a one-pot, three-component condensation of aldehydes, 1,3-dicarbonyl compounds, and urea or thiourea catalyzed by SSA under solvent-free conditions (Scheme 6.3). The main features of this method are its operational simplicity, good yields, use of cheap, commercially available chemicals, recyclability with the comparable activity of the catalyst, and that it is cost effective and environmentally benign. 

Benzoselenophene [111, 112] and related fused selenophenes [113-116] were previously obtained via tedious multistep reactions involving a selenocyclization reaction from barely accessible selenium-containing compounds. Such conventional synthetic methods are unsuitable for the development of selenophene-based OFET materials. Sashida s group developed a simple one-pot preparation of benzoselenophenes by an intramolecular selenocyclization reaction of acetylene compounds with a selenolate anion [117, 118]. This allowed straightforward access to sophisticated fused selenophenes, such as 52 and 53, from commercially available chemicals [119, 120]. Scheme 6.9 depicts the key selenocyclization reaction used in the synthesis of 52. This synthetic protocol was also successfully applied to the synthesis of regioisomer 54 [121]. 

A facile and efficient one-pot synthesis of luotonin F (78) and analogs was reported by the Wu group (130L378). Luotonin F (78) was prepared from commercially available 3-acetylquinoline (79) and 2-aminobenzamide (80), which when treated under optimal conditions in the presence of iodine (1.1 equiv.) and dimethyl sulfoxide (DMSO) at 110 °C, provided the desired compound in 72% yield (Scheme 36). 

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