University of Hawaii, 2545 The Mall, Honolulu, Hawaii 96822, USA.
Chem Soc Rev. 2014 May 7;43(9):2979-3002. doi: 10.1039/c3cs60333d. Epub 2013 Nov 6.
The ease of synthesis and the exceptional reactivity of alkoxyallenes has led to their use in a large number of highly diverse applications. This Report describes their use in various versions of the allene ether Nazarov cyclization. Following a brief introduction to the Nazarov cyclization (Section 1), the oxidative cyclization of vinyl alkoxyallenes is discussed first (Section 2). Nazarov cyclizations of α-alkoxyallenyl vinyl ketones and of α-alkoxyallenyl vinyl tertiary carbinols are covered (Section 3). The discovery and the subsequent rational design of acetals that serve as chiral auxiliaries on the allene in highly enantioselective Nazarov cyclizations is explained (Section 4). Interrupted Nazarov cyclizations of alkoxyallenes that are generated in situ from the isomerization of propargyl ethers on solid supports are discussed, including the evolution of a highly diastereoselective, chiral auxiliary controlled version of the reaction. Some applications of the methodology to natural products total synthesis have been included so as to provide the reader with benchmarks with which to judge the utility of the methodology.
由于烷氧基丙二烯的合成简便以及其特殊的反应活性，它们被广泛应用于许多高度多样化的领域。本报告描述了它们在各种形式的烯丙基醚 Nazarov 环化反应中的应用。在简要介绍 Nazarov 环化反应（第 1 节）之后，首先讨论了乙烯基烷氧基丙二烯的氧化环化反应（第 2 节）。涵盖了 α-烷氧基丙二烯基乙烯基酮和 α-烷氧基丙二烯基乙烯基三级醇的 Nazarov 环化反应（第 3 节）。解释了发现和随后对作为烯丙基上手性助剂的缩醛的合理设计，这些缩醛在高度对映选择性的 Nazarov 环化反应中发挥作用（第 4 节）。讨论了通过在固体载体上丙炔醚异构化原位生成的烷氧基丙二烯的中断 Nazarov 环化反应，包括反应的高度非对映选择性、手性助剂控制版本的发展。该方法学在天然产物全合成中的一些应用也被包括在内，以便为读者提供判断该方法学实用性的基准。
