Two-component coupling

Equimolar amounts (0.5 mmol) of 130 and 95 in 5 mL of absolute methanol were heated at 100°C for 24 h. The reaction was cooled to room temperature and the solvent removed. The crude product was recrystallized from methanol to afford 131 in 98% yield (mp = 125-126°C). 

Equimolar amounts (0.5 mmol) of 131 and chloranil in 2 mL of THE were heated at reflux for 4 h before cooling to room temperature and removing the solvent. Purification by preparative TLC gave 132 as an oil in 58% yield. 

Penieres, G. Garcia, O. Franco, K. Hernandez, O. Alvarez, C. Hetercyclic Commun. 1996, 2, 359-360 

Maquestiau, A. Mayence, A. Vanden Eynde, J.-J. Tetrahedron Lett. 1991, 32, 3839-3840 

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The highly functionalized hydroxypyrimidinone 3, the key intermediate for the synthesis of 1, was rapidly assembled by a two-component coupling reaction, followed by a thermal rearrangement. 

As described previously, the two-component coupling reaction between amidox-ime 50 and DM AD generated a mixture of Z- and E-adducts 51, which was heated in xylenes to afford hydroxypyrimidinone 55 (Scheme 6.20). The previously proposed mechanism involved tautomerization of 51 to 52, followed by a Claisen [3,3]-rearrangement to yield intermediate 53. Subsequent tautomerization of the intermediate 53 to 54, followed by cyclization would afford 55 [9a,f]. 

Spin-Orbit Effects Calculated by Two-Component Coupled-Cluster Methods Test Calculations on AuH, AU2, T1H and TI2. 

The asymmetric total synthesis of prostaglandin Ei utilizing a two-component coupling process was achieved in the laboratory of B.W. Spur. The hydroxylated side-chain of the target was prepared via the catalytic asymmetric reduction of a y-iodo vinyl ketone with catecholborane in the presence of Corey s CBS catalyst. The reduction proceeded in 95% yield and >96% ee. The best results were obtained at low temperature and with the use of the B-n-butyl catalyst. The 6-methyl catalyst afforded lower enantiomeric excess and at higher temperatures the ee dropped due to competing non-catalyzed reduction. 

An instructive and useful process is the two-component coupling of an alkene with an electrophilic radical the latter will of course not react with the protonated heterocycle, but after addition to the alkene, a nucleophilic radical is generated, which will react. ... 

Many methods have been developed for p-lactam synthesis, including cyclisation of the corresponding amino acids. The most widely used methods are two-component couplings, which occur via concerted cycloaddition or two-step mechanisms. Another simple route to 3-functionalised azetidinones is the reaction of aziridine-2-carboxylic acid sodium salt with oxalyl chloride or thionyl chloride. ... 

Note that the number of components reacting to form the ring is equal to the number of elements appearing in brackets. Hence, for a [3 -t 3] cycloaddition there are two elanents, so it is a two-component coupling reaction. The number of bond disconnections equals the number of components reacting. Note also that the sum of the elanents is 6, which correspouds to the monocycle ring size. 

Y. S. Lee. Spin-orbit effects calculated by two-component coupled-duster methods test calculations on AuH, Au2, HH and TI2. Chem. Phys. Lett., 293 (1998) 97-102. 

Han, Y.-K., Hirao, K. Two-component coupled-cluster calculations for the hydride of element 111 on the performance of relativistic effective core potentials. Chem. Phys. Lett. 328, 453 58 (2000)... 

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