- Highly stereoselective, one-pot synthesis of azetidines and 2,4-dioxo-1,3-diazabicyclo[3.2.0] compounds mediated by I2
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We report here a convenient method to construct polysubstituted azetidines and 2,4-dioxo-1,3-diazabicyclo[3.2.0] compounds with high stereoselectivities in a one-pot reaction mediated by I2. The tetramethylguanidine (TMG)/I2-mediated formal [2 + 2] cycloaddition reaction of α-amidomalonate 1 with enones 2 affords functionalized azetidine derivatives 4 in moderate to good yields with high diastereoselectivity. When the α-ureidomalonate 5 is used instead of 1, 2,4-dioxo-1,3-diazabicyclo[3. 2.0]heptanes 8 and 2,4-dioxo-1,3-diazabicyclo[3.2.0]heptenes 9 can be prepared selectively through the control of solvent and temperature. 2,4-Dioxo-1,3- diazabicyclo[3.2.0]heptanes 8 can further undergo ring-opening reactions with different nucleophilic reagents to afford the corresponding polyfunctionalized azetidine derivatives 13-16 with high steroselectivities.
- Miao, Chun-Bao,Dong, Chun-Ping,Zhang, Min,Ren, Wen-Long,Meng, Qi,Sun, Xiao-Qiang,Yang, Hai-Tao
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p. 4329 - 4340
(2013/06/05)
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