Mesomorphic behavior of new azomethine liquid crystals having terminal iodo group
作者:Sie-Tiong Ha、Teck-Leong Lee、Guan-Yeow Yeap、Masato M. Ito、Ayumu Saito、Masaaki Watanabe
DOI:10.1016/j.cclet.2010.09.017
日期:2011.3
possessing even number of carbon atoms at the terminal alkanoyloxy chain (Cn-1H2n-1COO-, n = 4,6,8,10,12,14) was synthesized. n-Butanoyloxy was found non-mesogenic, whilst n-hexanoyloxy to n-tetradecanoyloxy exhibited enantiotropic smectic A phase with fan-shaped texture. It was found that the length of terminal alkanoyloxy chain influenced the mesomorphic properties.
一系列偶氮甲酸酯,在末端烷酰氧基链上具有偶数碳原子的3-羟基-4-[((4-碘苯基)亚氨基]甲基}苯基}链烷酸酯(C n-1 H 2n-1 COO-,n = 4,6,8,10,12,14)被合成。Ñ -Butanoyloxy发现非介晶,同时Ñ -hexanoyloxy到Ñ -tetradecanoyloxy展出互变近晶A与扇形纹理相。发现末端烷酰氧基链的长度影响介晶性质。
Promotion of a Ti-Mediated Mannich Reaction by a Proton Source
作者:John Limanto、Naoki Yoshikawa、Robert A. Reamer、Lushi Tan、Andrew Brunskill、Mikhail Reibarkh
DOI:10.1021/acs.joc.5b02452
日期:2016.1.15
Low temperature NMR studies revealed that a diastereoselective Mannich reaction between a phenyl oxazolidone-derived titanium enolate and an aromatic aldimine was found to occur only after introduction of a proton source. While various protic additives could be used to promote the transformation, the best results were obtained using AcOH to afford the corresponding Mannich products in high diastereoselectivities and yields.