Synthesis ( IF 2.2 ) Pub Date : 2020-07-29 , DOI: 10.1055/s-0040-1707207 Xavier Companyó 1 , Alessio Calcatelli , Alessio Cherubini-Celli , Edoardo Carletti
Dedicated to Professor Albert Moyano on the occasion of his 65th birthday
Abstract
Morita–Baylis–Hillman (MBH) adducts are versatile starting materials widely employed in Lewis base catalysis. A myriad of different transformations have been reported based on either allylic alkylations with stabilised nucleophiles or annulations with diverse dipolarophiles. Apart from these two conventional types of reactivity, MBH adducts have recently been implemented in alternative and complementary catalytic strategies, including: (i) one-pot and cascade transformations, where additional chemical bonds are formed following the asymmetric allylic alkylation event in a single synthetic operation; (ii) regioselective α-allylations for the synthesis of trisubstituted alkenes; and (iii) dual activation strategies, involving Lewis base catalysis together with transition metal complexes or light, enabling allylic alkylations with nonstabilised nucleophiles and cascade processes. The present Short Review summarises the most significant unconventional catalytic transformations of racemic MBH adducts reported within the last decade.
1 Introduction
2 Multi-Step Single-Vessel Transformations (path iii)
2.1 One-Pot Transformations
2.2 Cascade Transformations
3 α-Allylations (path iv)
3.1 SN2′ Mechanism
3.2 SN2′–SN2 Mechanism
3.3 Miscellaneous Mechanisms
4 Dual Activation (path v)
4.1 MBH Adduct as Electrophile
4.2 MBH Adduct as Nucleophile
5 Summary and Outlook
中文翻译:
Morita–Baylis–Hillman加合物的非常规转变
献给阿尔伯特·莫亚诺(Albert Moyano)教授65岁生日
抽象
Morita–Baylis–Hillman(MBH)加合物是通用的原料,广泛用于Lewis碱催化中。已经报道了基于具有稳定的亲核试剂的烯丙基烷基化或具有多种亲二性亲核试剂的环化反应的无数种不同的转化。除了这两种常规类型的反应性以外,MBH加合物最近还用于替代和互补的催化策略中,包括:(i)一锅法和级联转化,其中在不对称的烯丙基烷基化事件后,在单个合成物中形成额外的化学键操作 (ii)用于合成三取代烯烃的区域选择性α-烯丙基化;(iii)双重活化策略,包括路易斯碱催化以及过渡金属络合物或光,使用不稳定的亲核试剂和级联过程实现烯丙基烷基化。本简报总结了过去十年中报道的外消旋MBH加合物最重要的非常规催化转化。
1引言
2多步单船转换(路径iii)
2.1一锅转换
2.2级联转换
3个α-烯丙基化(路径iv)
3.1 S N 2′机制
3.2 S N 2′–S N 2机理
3.3其他机制
4双重激活(路径v)
4.1 MBH加成物为亲电试剂
4.2 MBH加合物作为亲核试剂
5总结与展望