HETERO HEAD-TO-HEAD DIMER BY TOPOCHEMICAL PHOTOREACTION OF METHYL Α-Cyano-4-[2-(2-Pyridyl)ethenyl]cinnamate

Abstract

Methyl α-cyano-4-[2-(2-pyridyl)ethenyl]cinnamate crytstal shows a high photoreactivity to form the dimer of single structure quantitatively. This result is a unique example in such point that the topochemical photoreaction of β-form diolefin crystals gives neither of the polymer nor the cyclic dimer, but the photostable diolefinic dimer.

Topochemical photoreactions of unsymmetrically substituted diolefins. 2. Photopolymerization of 4'-(alkoxycarbonyl)-2,5-distyrylpyrazines

“…2b: IR (KBr) 1715 (s), 1610 (m), 1480 (m), 1280 (s), 1105 (s), 1020 (m), 700 (s) cm"1; XH NMR (400 MHz in TFA) 8.85 (s, 1 H), 8.69 (s, 1 H), 7.99 (d, 2 ), 7.40-7.00 (m, 7 ), 5.40-4.40 (br m, 6 ), 1.54 (t, 3 H); UV (e in HFIP) 284.0 (9900), 238.2 nm (17 900). 2c: IR (KBr) 1720 (s), 1615 (m), 1500 (m), 1280 (s), 1110 (s), 940 (m), 700 (m) cm"1; NMR (400 MHz in TFA) 8.85 (s, 1 ), 8.00 (d, 2 ), 7.40-7.00 (m, 7 ), 5.50-4.40 (br m, 6 ), 1.98 (m, 2 ), 1.16 (t, 3 H); UV (c in HFIP) 284.8 (10600), 240.2 nm (19 300). 2d: IR (KBr) 1720 (s), 1620 (m), 1480 (m), 1290 (s), 1120 (s), 1020 (m), 700 (m) cm"1; NMR (400 MHz in TFA) 8.85 (s, 1 H), 8.72 (s, 1 ), 8.00 (d, 2 ), 7.30-7.05 (m, 7 ), 5.45-4.40 (br m, 6 ), 1.94 (q, 2 ), 1.05 (t, 3 H); UV (e in HFIP) 284.2 (8000), 240.1 nm (14200).…”

Solvent‐Free Photosynthesis of Cyclobutanes: Photodimerization of Crystalline Olefins

“…,Scheme 36 198,[201][202][203] , Scheme 37204 -207 , Scheme 38207 -209 , Scheme 39204 -207, 210 -216 , Scheme 4037, 217 -223 , Scheme 41218, 219, 224 -233 and Scheme 42225,230,232,233 . No examples of two-component crystal dimerizations and polymerizations are included.…”