Isomiinchnones synthesis reactions

Mathias and Moore (30-33) described a new synthesis of isomiinchnones 55 via the thermal cyclization of A-(chloroacetyl)lactams (54) (Scheme 10.7). These isomiinchnones can be captured by NPM to give fused 2-pyridones in moderate yields. Cycloadducts from the reaction with DMAD are produced in much lower yields (<17%), and other olefinic dipolarophiles (fumarate, maleate, acrylate, and dicyanocyclobutene) are unreactive. Reaction of 7/-(chloroacetyl)benzamide (57) in the presence of NPM gave 58 in low yield. 

Gowravaram and Gallop (169) adapted the rhodium-catalyzed generation of isomiinchnones from diazo imides to the solid-phase synthesis of furans, following a 1,3-dipolar cycloaddition reaction with alkynes. A variety of furans were prepared in this fashion. With unsymmetrical electron-deficient alkynes (e.g., methyl... 

A traceless linker strategy for the synthesis of functionalised furans based on mesoionic isomiinchnones generated on solid support, was developed by Gallop et alP- The key step of this protocol takes advantage of an efficient [3+2] cycloaddition reaction with electron deficient acetylenes, followed by a thermally promoted cycloreversion reaction. 3- 7 As shown in Scheme... 

Kappe and co-workers have extended their intermolecular isomiinch-none cycloaddition reaction (see Scheme 26) to an intramolecular version to obtain the conformationally rigid polyheterocycles 206, which mimic the putative receptor-bound conformation of dihydropyrimidine-type calcium channel modulators [159]. The key step in the synthesis involves the regio- and diastereoselective intramolecular 1,3-dipolar cycloaddition reaction of a dihydropyrimidine-fused isomiinchnone dipole. The diazoimides... 

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