Novel photoactive compounds, processes for their production and intermediates therefor
申请人:MTM RESEARCH CHEMICALS LIMITED
公开号:EP0334477A3
公开(公告)日:1989-12-27
Photoactive compounds having the general formulae below are provided
in which A represents oxygen or specified imido groups;P' represents a 3-furyl, a 3-thienyl, a 3-pyrryl, a 3-benzofuryl or a 3-benzothienyl group, said 3-furyl, 3-thienyl and 3-pyrryl groups which is unsubstituted or substituted in the 2-position and/or the 5-position, with specified substituents;p2 represents alkyl having 1 to 20 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, aralkyl having 7 to 9 carbon atoms, aryl having 6 to 14 carbon atoms which may be unsubstituted or substituted with one or more halogen atoms, or alkaryl having 7 to 22 carbon atoms; andF>C* and E>C* represent a substituted or unsubstituted bridged polycyclic hydrocarbon residue containing from 7 to 20 carbon atoms in a polycyclic system, said residue having a plane of asymmetry which is parallel to the plane which includes the single bonds extending from carbon atom C* and the anhydride or imide ring, any substituents on the bridged polycyclic hydrocarbyl residue being selected from alkyl groups having 1 to 4 carbon atoms, halogen atoms and hydroxy groups.
Furylfulgides with different sizes of alkyl substituents were synthesized and their photochromic properties were examined. While the quantum yield of coloring reaction increased and the quantum yield of the E-to-Z isomerization decreased as the steric bulkiness of the alkyl substitutent on the 2,5-dimethyl-3-furylmethylidene moiety increased, the bleaching quantum yield increased as the isopropylidene
as the catalyst. The reaction at 90 °C under 80 atm of carbon monoxide for 5 h directly gave both E and Z isomers of t-butyl-substituted furyl- or thienyl fulgides. The former had been reported impossible to synthesize by the Stobbe condensation. Similarly, furyl- and thienylfulgides with an isopropyl group were synthesized by this method. The fulgides were isolated by column chromatography in 37—75%
2,6,6-三甲基-5-(2,5-二甲基-3-呋喃基和-3-噻吩基)-3-庚炔-2,5-二醇在苯中在 1:1-Pd( OAc)2/I2 作为催化剂。在 90°C 和 80 个大气压的一氧化碳下反应 5 小时,直接得到叔丁基取代的呋喃基或噻吩基强酸酐的 E 和 Z 异构体。据报道,前者不可能通过 Stobbe 缩合合成。类似地,通过这种方法合成了带有异丙基的呋喃基和噻吩基硫辛酸。通过柱层析分离出产率为 37-75% 的强酸酐。叔丁基-呋喃基-和-噻吩基强酸酐的着色量子产率分别为0.79和0.73,在具有相同杂芳环的各系列强酸酐中最高。
Fulgides as Efficient Photochromic Compounds. Role of the Substituent on Furylalkylidene Moiety of Furylfulgides in the Photoreaction
Quantum yields of photoreactions of furylfulgides having Me, Et, n-Pr, or i-Pr on the furylalkylidene moiety were measured. The E–Z isomerization was greatly suppressed and the cyclization was accelerated when the alkyl group (R) became bulkier. When R was i-Pr, no E–Z isomerization was observed and the quantum yield of the colorizing cyclization was 0.62.