A Novel Strategy of Absolute Asymmetric Synthesis via Spin Coating

不使用手性催化剂制备不对称化合物的“绝对不对称合成”在各种研究领域引起了极大的兴趣，其目的是建立用于合成不对称化合物的有效方法以及研究自然界中手性对称性破缺的起源。利用手性晶体进行绝对不对称合成是迄今为止报道的一个成功的例子，其中某些非手性化合物在晶体堆积中形成单手螺旋排列。然而，这种策略只允许用于特殊的基板。另一方面，利用圆偏振光的不对称光反应也被认为是绝对不对称合成的有效方法。然而，在这个过程中，我们必须制作一个特殊设计的偏振光发生器，而且，手征对称性破缺通常发生在低产量。在此背景下，我们研究了一种可能的绝对不对称合成使用物理手性刺激，如旋涂和搅拌的溶液。分子手性的机械控制是合成化学的一大挑战，其允许通过旋转盘或搅拌棒的方向（顺时针或逆时针）选择性地合成一种对映体。迄今为止，还没有相关研究成果的报道，我们期待着我们的研究成果在手性科学中的普遍应用。在本研究中，我们成功地发现了一些有趣的分子事件，这极大地推动了现代手性科学的发展。

'Absolute asymmetric synthesis', which produces asymmetric compounds without using a chiral catalyst, has attracted much interest in various research fields, in the purpose of establishment of an effective methodology for synthesis of the asymmetric compounds as well as investigation of an origin of chiral symmetry breaking in nature. A successful example so far reported in the absolute asymmetric synthesis has been developed by utilization of the chiral crystals, where certain achiral compounds form a one-handed helical alignment in the crystal packing. However, this strategy has been only allowed to utilize for special substrates. On the other hands, asymmetric photoreactions using circularly polarized lights have been also believed as an effective methodology of the absolute asymmetric synthesis. However, in this procedure, we have to make a specially designed polarized light generator, and further, the chiral symmetry breaking occurs usually in low yield. With this background, we have studied a possible absolute asymmetric synthesis using physical chiral stimuli such as spin-coating and stirring of the solution. Mechanical control of the molecular chirality is a big challenge of synthetic chemistry, which allows selective synthesis of one of the enantiomers by rotating direction (clockwise or counterclockwise) of the disk or stirring bar. To date, no related achievements have been reported for this subject, we have expected universal utilization of our research achievements in the chiral sciences. In the present study, we have succeeded in finding some interesting molecular events, which highly advances the modern chiral sciences.