Development of fluorinated ferroelectric liquid crystals through an enzymatic reaction.

铁电液晶（FLC）是一种重要的高速开关器件，其响应时间与自发极化的大小密切相关。最近的一项研究表明，含有光学活性1,1,1-三氟-2-烷醇的手性FLC化合物具有Sc^<**>相温度范围宽、自发极化大、响应时间短的显著特性。由于目标化合物是FLC化合物，因此特别需要大规模制备。以醋酸乙烯基为给体，利用南极假丝酵母脂肪酶（CAL）催化己烷酯化反应，成功地进行了外消旋1,1,1-三氟-2-烷醇的光学拆分，得到了光学纯净状态的相应(S) -乙酸酯。通过更多cal催化的酰化反应，得到了1,1,1-三氟-2-辛醇、1,1,1-三氟-2-壬醇、1,1,1-三氟-2-癸醇、1,1,1-三氟-2-癸醇和1,1,1-三氟-8-苄基-2-辛醇五种光学纯烷醇。具有手性双（三氟甲基）烷二醇部分的反铁电液晶（AFLCs）化合物也被认为是重要的高速开关器件。已证实双（三氟甲基）烷二醇二乙酸酯的对映选择性水解。CAL是一种最能对二乙酸酯的乙酰基进行对映选择性水解的酶，得到五种光学纯的二醇和二乙酸酯。在cal催化反应得到的化合物中，1,4-二（1,1,1-三氟-2-十二烷基）苯已成功转化为一种新的AFLCs化合物。脂酶催化反应可用于大规模制备，因此本方法为制备光学纯1,1,1-三氟-2-烷醇和双（三氟甲基）烷二醇提供了一种有价值的方法。因此，制造铁电和反铁电液晶的关键化合物是通过酶生成作为关键反应而开发出来的。少

Ferroelectric liquid crystals (FLC) are known to be important high-speed switching devices, and their response time strongly depends on the magnitude of spontaneous polarization. A recent study revealed that chiral FLC compounds which involve optically active 1,1,1-trifluoro-2-alkanols possess remarkable characteristics of a wide temperature range of Sc^<**> phase, a large spontaneous polarization, and a short responsetime. Becausethe target compounds are FLC compounds, large scale preparation is particularly desired. Candida antarctica-lipase (CAL) -catalyzed esterification in hexane using vinyl acetate as acyl donor was successfully utilized for optical resolution of racemic 1,1,1-trifluoro-2-alkanols to provide corresponding (S) -acetates in an optically pure state. Five types of optically pure alkanols, i.e.1,1,1-trifluoro-2-octanol, 1,1,1-trifluoro-2-nonanol, 1,1,1-trifluoro-2-decanol, 1,1,1-trifluoro-2-undecanol, and 1,1,1-trifluoro-8-benzylo-2-octanol, were thus obtained by the … More CAL-catalyzed acylation.Antiferroelectric liquid crystal (AFLCs) compounds, which possess a chiral bis (trifluoromethyl) alkanediol moiety, are also known to be important high-speed switching devices. Enantioselective hydrolysis of diacetates of bis (trifluoromethyl) alkanediols has been demonstrated. CAL was chosen from among commercial enzymes as the one most able to enantioselectively hydrolyze the acetyl group of diacetates giving five types of optically pure diols and diacetates. Among compounds obtained by CAL-catalyzed reaction, 1,4-bis (1,1,1-trifluoro-2-dodecanyl) benzene has been successfuly converted to a new AFLCs compound.The lipase-catalyzed reaction can be used in a large scale preparation, the present method therefore affords a valuable method of preparing optically pure 1,1,1-trifluoro-2-alkanols and bis (trifluoromethyl) alkanediols. Key compounds for making ferroelectric and antiferroelectric liquid crystals were thus developed via an enzymaticreaction as a key reaction. Less