Cu-catalyzed <i>N</i>-3-Arylation of Hydantoins Using Diaryliodonium Salts
作者:Linn Neerbye Berntsen、Ainara Nova、David S. Wragg、Alexander H. Sandtorv
DOI:10.1021/acs.orglett.0c00642
日期:2020.4.3
A general Cu-catalyzed, regioselective method for the N-3-arylation of hydantoins is described. The protocol utilizes aryl(trimethoxyphenyl)iodonium tosylate as the arylating agent in the presence of triethylamine and a catalytic amount of a simple Cu-salt. The method is compatible with structurally diverse hydantoins and operates well with neutral aryl groups or aryl groups bearing weakly donating/withdrawing
Access to combinatorial chemistry of hydantoins is provided by convenient and versatile methods for the solidphasesynthesis of libraries of 3,5-, 1,3- and 1,3,5-substituted hydantoins. The preparation of trisubstituted hydantoins features a Mitsunobu reaction for introduction of the substituent on N-1.
Silver halide light sensitive emulsion layer having enhanced photographic sensitivity
申请人:EASTMAN KODAK COMPANY
公开号:EP0786692A1
公开(公告)日:1997-07-30
A photographic element comprises at least one silver halide emulsion layer in which the silver halide is sensitized with a compound of formula
Z-(L-XY)k
wherein:
Z is a light absorbing group;
L is a linking group containing a least one
C, N, S, or O atom; and
k is 1 or 2; and
XY represents a fragmentable electron donor moiety wherein:
1) XY has a an oxidation potential between 0 and about 1.4 V;
2) X is an electron donor group;
3) Y is a leaving group other than hydrogen; and
4) the oxidized form of XY undergoes a bond cleavage reaction to give the radical X• and the leaving fragment Y.
In a preferred embodiment the radical X• has an oxidation potential of ≤ -0.7 V.
感光元件包括至少一个卤化银乳剂层,其中的卤化银是用式 1 的化合物感光的。
Z-(L-XY)k
其中
Z 是光吸收基团
L 是连接基团,含有至少一个
C、N、S 或 O 原子的连接基团;以及
k 是 1 或 2;以及
XY 代表可碎裂的电子供体分子,其中
1) XY 的氧化电位在 0 至约 1.4 V 之间;
2) X 是电子供体基团
3) Y 是氢以外的离去基团;以及
4) XY 的氧化形式发生键裂反应,生成自由基 X- 和离去片段 Y。
在一个优选的实施方案中,自由基 X- 的氧化电位≤ -0.7 V。
Photobleachable composition, photographic element containing the composition and photobleach method
申请人:EASTMAN KODAK COMPANY
公开号:EP1134613A1
公开(公告)日:2001-09-19
A UV or visible-light sensitive photobleachable dye composition substantially free of polymerisable monomer comprising a photobleachable dye and an N-oxyazinium compound, a photographic element containing such a photobleachable composition, and a method for bleaching a photographic element.