CHIRAL TRIOLS OF C3-SYMMETRY: SYNTHESIS AND APPLICATION TO CHIRAL RECOGNITION

我们设计了新的不对称硼介导的双羟醛缩合反应，其互补地可用于通过手性乙酸酯或手性乙酰基恶唑烷酮的双羟醛缩合反应合成具有C3-对称性的脂肪族和芳香族取代的手性三醇，所述手性三醇是研究不对称催化和手性识别的潜在前体。合成了3 ~ 5代5-二取代苄基醚型树枝状酮<rd><th>。对这些树枝状大分子的手性性质进行了研究，发现它们具有“稀释效应”，没有观察到“分子手性”的证据。合成了三吡啶和三联吡啶取代的化合物，研究了它们的金属配合物的性质。合成了三-2-吡啶甲基和三-3-吡啶甲基取代的手性三醇。ESI-MS测定表明，它们的铜配合物分别为1：1和2：1。用5 ′-甲基-5-氯甲基-2，2 ′-联吡啶处理三-6 ′-甲基-6-（2，2 -联吡啶甲基）取代的三醇，没有得到钌配合物，产率很低（&lt;10%）。将执行使用甲锡烷基吡啶和2-溴吡啶基甲基取代的手性三醇的Stille偶联的替代途径。

We have devised new asymmetric boron-mediated double aldol reactions complementarily useful for the synthesis of aliphatic and aromatic substituted chiral triols of C3-symmetry, which are potential precursors for the study of asymmetric catalysis and chiral recognition, via double aldol reactions of a chiral acetate ester or a chiral acetyloxazolidinone.Chiral dendrimenrs having a chiral triol of C3-symmetry as a core element with 3, 5-disubstituted benzyl ether type dendrone of the 3^<rd> to 5^<th> generation were synthesized. The chiroptical properties of these dendrimers were examined and shown to exibhit the "dilution effect", eveidence of their of "molecular chirality being not observed.Tris-pyridine, and tris-bipyridine substituted compounds were synthesized to examine properties of their metal complexes. Tris-2-pyridylmethyl and tris-3-pyridylmethl substituted chiral triols were synthesized. Their copper complexes were shown to be 1: 1, and 2: 1 complex, respectively, by ESI-MS measurement. Catalytic of these complexes was examined.Tris-6'-methyl-6-(2, 2 -bipyridylmethyl) substituted triols did not afford Ru complex upon treatment with 5'-methyl-5-chloromethy-2, 2'bipyridine proceeded only low yield (<10%). An alternate route using Stille coupling of stannylpyridine and 2-bromopyridylmethyl substituted chiral triols will be executed.