可见光催化的硅烷二氟烯丙基化反应_杨春晖.pdf

研究通讯 Communication *E-mail:; Received November 9,2022;published January 3,2023.Supporting information for this article is available free of charge via the Internet at http:/sioc-.Project supported by the National Natural Science Foundation of China(Nos.21961045,22061048)and Yunnan Provincial Key Laboratory Construction Plan Funding of Universities and Yunnan Provincial Engineering Research Center Construction Plan Funding of Universities.项目受国家自然科学基金(Nos.21961045,22061048)及云南省高校重点实验室建设计划和云南省工程技术研究中心建设计划资助.Acta Chim.Sinica 2023,81,15 2023 Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences http:/sioc- 1 化 学 学 报 化 学 学 报 ACTA CHIMICA SINICA 可见光催化的硅烷二氟烯丙基化反应 杨春晖a 陈景超*,a 李新汉b 孟丽b 王凯民b 孙蔚青b 樊保敏*,a,b(a云南民族大学 民族医药学院 民族药资源化学国家民委-教育部重点实验室 昆明 650504)(b云南民族大学 化学与环境学院 云南民族大学高等合成化学重点实验室 昆明 650504)摘要摘要 研究了在蓝光照射下,以奎宁环作为氢原子转移试剂,实现了硅烷与-三氟甲基烯烃的无金属二氟烯丙基化反应,并且通过使用多种芳香族和杂环-三氟甲基烯烃,均能成功得到二氟烯丙基硅烷.本研究为制备二氟烯丙基硅烷提供了一种高效且经济的克级合成方法.关键词关键词 -(三氟甲基)苯乙烯;硅烷;光催化;二氟烯丙基硅烷;奎宁环 Difluoroallylation of Silanes under Photoirradiation Difluoroallylation of Silanes under Photoirradiation Yang,Chunhuia Chen,Jingchao*,a Li,Xinhanb Meng,Lib Wang,Kaiminb Sun,Weiqingb Fan,Baomin*,a,b(a School of Ethnic Medicine,Key Laboratory of Chemistry in Ethnic Medicinal Resources,State Ethnic Affairs Commission&Ministry of Education,Yunnan Minzu University,Kunming 650504,China)(b School of Chemistry and Environment,Key Laboratory of Advanced Synthetic Chemistry,Yunnan Minzu University,Kunming 650504,China)Abstract The synthesis of organosilicon compounds has attracted considerable interest,especially the allyl silanes,which are regarded as ideal building blocks in the synthesis of small molecules and polymers.The traditional synthetic method for allyl silanes relies on the cross-coupling of Grignard reagent and chlorosilane(Silyl-Kumada reaction),transition metal cata-lyzed silylation of allylic alcohols with disilanes or silylboranes,and regioselective silylation of conjugated alkenes or al-lenes.Although some other methods were also developed,the using of transition metal catalysts has resulted in disadvantages such as contamination of desired allyl silanes and high production costs.Therefore,a mild and metal-free practical method is highly desired.We herein describe a metal-free difluoroallylation of silanes with-trifluoromethyl alkenes in the presence of quinuclidine as hydrogen atom transfer(HAT)reagent under the irradiation of 30 W blue light-emitting diode(LED)(460470 nm)at room temperature.To an oven dried Schlenk-tube,trifluoromethylpropene(0.1 mmol),silane(0.3 mmol),KHCO3(0.1 mmol),4-CzIPN(1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene)(0.002 mmol)and MeCN(1 mL)were added un-der argon atmosphere.The reaction mixture was stirred under the irradiation of 30 W blue LED(460470 nm)at room tem-perature.After completion of the reaction,the reaction solution was removed by reduced pressure and the residue was puri-fied by silica gel chromatographic column to obtain gem-difluoroallylation products.A wide range of aromatic and heterocy-clic-trifluoromethyl alkenes were successfully applied in the difluoroallylation of silanes to afford difluoroallylsilanes.And all of the tested silanes,including trimethylsilane,sterically more demanding silanes as well as dimethylphenylsilane all par-ticipated in the present transformation readily to afford the corresponding difluoroallylsilanes in excellent yields.The present methodology has provided an efficient and cost-effective gram scale synthetic method for the preparation of difluoroal-lylsilanes under blue light irradiation in the presence of 4-CzIPN as organic photosensitizer.The scalability in large scale and excellent functional group compatibility of this transformation ensures broad applicability to a variety of difluoroallylsilanes.The proposed reaction mechanism showed that the reaction proceeded through the radical addition of-trifluoromethyl al-kene with silane free radical and subsequent-fluoride elimination.Keywords -(trifluoromethyl)styrenes;silane;photocatalysis;difluoroallylsilane;quinuclidine 1 引言 硅和碳是同一主族的连续元素,因此硅可以替代大量有机化合物中的碳原子,从而形成有机硅化合物,并表现出不同的化学、物理和生物性能.由于通过基因组学、平行化学和高通量生物学成功实现的药物研究和开发的例子较少,所以药物开发行业一直需要通过寻找新的“类似药物”的候选药物来降低风险和成本.用硅原DOI:10.6023/A22110454 化化 学学 学学 报报 研究通讯 2 http:/sioc- 2023 Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences Acta Chim.Sinica 2023,81,15 子取代现有药物中的碳原子以寻找新的“类似药物”的候选药物,已成为药物化学研究中一种具有吸引力的策略.例如,Sieburth 团队1制备了硅烷二醇并证明它们可以穿过细胞膜并展示出抗病毒作用.据报道,含硅多肽模拟物是金属蛋白酶血管紧张素转换酶的有效抑制 剂2.吲哚美辛的硅衍生物被发现比原来的吲哚美辛表现出更强的抗癌活性3.非天然含硅氨基酸已被证明具有增强的亲脂性、增加的抵抗力和细胞对蛋白水解降解的摄取4.硅取代的氟哌啶醇是多巴胺拮抗剂氟哌啶醇的硅类似物,对 hD2受体的亲和力比氟哌啶醇高五倍5.另一方面,由于其稳定性、溶解性、无毒性和与有机金属试剂相比易于处理的优点,在适当的碱活化下,有机硅化合物经常作为多功能烯丙基阴离子等价物而广泛应用于多种合成转化中6.有机硅化合物的合成引起了研究者们相当大的兴趣.特别是烯丙基硅烷,它们被认为是小分子和聚合物合成中的理想砌块7.传统的烯丙基硅烷合成方法有格氏试剂与氯化硅烷的交叉偶联反应(Silyl-Kumada 反应)8,过渡金属催化烯丙基醇与二硅烷或硅基硼烷的硅烷化反应9,共轭烯烃或烯丙烷的选择性硅烷化反应等10.尽管还发展了一些其他二氟烯丙基硅烷的合成方法11,但过渡金属催化剂的使用给这些转化造成了较大局限,比如制备烯丙基硅烷时造成的环境污染和较高的生产成本等.因此,发展一种温和且无金属的实用方法很有必要,在本文的撰写的过程中,光催化烯丙基化曾被报道12.近年来,光催化偶联反应