Synthesis of AcrylonitrilesviaMild Base Promoted Tandem NucleophilicSubstitution‐Isomerizationofα‐CyanohydrinMethanesulfonates
Synthesis of AcrylonitrilesviaMild Base Promoted Tandem NucleophilicSubstitution‐Isomerizationofα‐CyanohydrinMethanesulfonates
复制标题
弱碱促进串联亲核取代合成丙烯腈——氰醇甲磺酸盐异构化
DOI：
10.1002/cjoc.202000579
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发表时间：
2021
影响因子：
5.4
通讯作者：
Xu, Bo
中科院分区：
文献类型：
--
作者：
Liu, Shiwen;Meng, Lingling;Zeng, Xiaojun;Hammond, Gerald B.;Xu, Bo
丙烯腈是重要的目标和非常有用的构件，可以转化为许多官能团，如羧酸、[1]胺[2]和醛。[3]更具体地说，丙烯腈参与各种转化，如Michael加成反应、Diels-Alder环加成反应[5]和交叉偶联反应。此外，丙烯腈仍然是制备塑料、丙烯纤维和聚丙烯腈的常用单体之一。[7]此外，丙烯腈基序代表了许多药物和天然产品中常见的结构基元，如entacapone(治疗帕金森病的药物)、CC-5079(抗肿瘤药物)、传统的合成丙烯腈的方法是基于经典的Knovenagel缩合反应、[9]Wittig反应[10](方案1a)、Heck或氧化Heck反应[11](方案1b)、丙烯酰胺或共轭肟脱水(方案1c)、[12]烯烃卤化物氰化(方案1d)、[13]烯烃氰化(方案1e)[11c，14]和烯丙基氰化[15]。这些方法通常存在底物范围小和/或E/Z选择性低的问题。最近，酱和他的同事报道了一种有效的碱促进芳基乙腈与末端炔的加成[16](方案1f)，尽管需要强碱(KOtBu)，但它为制备丙烯腈提供了一种直接和无过渡金属的方案。另一方面，Pd催化的有机硼酸与α-氰醇三氟酸酯的铃木交叉偶联反应已由Falck及其同事报道(方案1g)。此外，唐、[19]Wang、[20]Huang、[21]Ryu[22]和US[23](方案1h)的团队也很好地探索了烯基或芳基硼酸的无金属铃木交叉偶联反应[18]。
Nitriles are important targets and highly useful building blocks which can be transformed to many functionalities such as carboxylic acids,[1] amines [2] and aldehydes.[3] More specifically, acrylonitriles involved in various transformations, such as Michael addition,[4] Diels-Alder cycloadditions [5] and cross-couplings.[6] Besides, acrylonitriles remain one of commonly used monomers for preparation of plastics, acrylic fibers and polyacrylonitrile.[7] Moreover, the acrylonitrile motif represents a common structural motif frequently found in many pharmaceuticals and natural products such as Entacapone (agent for Pakinson's disease), CC-5079 (antitumor agent), Rilpivirine (reverse transcriptase inhibitor).[8] Thus, their efficient synthesis has been a longstanding goal of organic synthesis.Traditional methods for the synthesis of acrylonitriles are based on the classical Knoevenagel condensations,[9] Wittig-type reactions [10](Scheme 1a), Heck or oxidative Heck-type reactions [11](Scheme 1b), dehydration of acrylamides or conjugated oximes (Scheme 1c),[12] cyanation of alkenyl halides (Scheme 1d),[13] cyanation of alkynes (Scheme 1e)[11c, 14] and allylic cyanation.[15] However, these methods usually suffer from poor substrate scope and/or low E/Z selectivity. Recently, Jiang and coworkers reported an efficient base promoted addition of arylacetonitriles to terminal alkynes [16](Scheme 1f), providing a straightforward and transition metal-free protocol for the preparation of acrylonitriles although strong base (KOtBu) was needed. On the other hand, Pd catalyzed Suzuki cross-coupling of organoboronic acids with α-cyanohydrin triflates has been reported by Falck and coworkers (Scheme 1g).[17] Also, metal-free Suzuki type cross-couplings [18] of alkenyl or aryl boronic acids have been well explored by groups of Tang,[19] Wang,[20] Huang,[21] Ryu [22] and us [23](Scheme 1h).