Effect of Additives on Chemoselectivity and Diastereoselectivity in the Catalytic Epoxidation of Chiral Allylic Alcohols with Hydrogen Peroxide and Binuclear Manganese Complexes
作者:Hamdullah Kilic、Waldemar Adam、Paul L. Alsters
DOI:10.1021/jo801974e
日期:2009.2.6
chiral allylicalcohols 2 by manganese complexes of the cyclic triamine 1,4,7-trimethyl-1,4,7-triazacyclononane (tmtacn) 1 and hydrogen peroxide as oxygen donor in the presence of co-catalyst are investigated to understand the factors that affect the catalyst selectivity. Chemoselectivity and diastereoselectivity of catalyst 1 are significantly affected by the structure of the allylicalcohol and the
研究了在助催化剂存在下,环状三胺1,4,7-三甲基-1,4,7-三氮杂环壬烷(tmtacn)1和过氧化氢作为氧供体的锰配合物对手性烯丙基醇2的催化氧化,了解影响催化剂选择性的因素。烯丙醇的结构以及助催化剂的性质和量显着影响催化剂1的化学选择性和非对映选择性。H 2 O 2的添加摩尔当量(相对于基材为20-110 mol%)的影响更为明显。我们目前的结果反映了Mn催化剂1 / H 2的复杂氧化还原化学反应O 2 /助催化剂体系在烯烃氧化的早期阶段。
Highly Enantio- and Diastereoselective One-Pot Synthesis of Acyclic Epoxy Alcohols and Allylic Epoxy Alcohols
作者:Ann Rowley Kelly、Alice E. Lurain、Patrick J. Walsh
DOI:10.1021/ja051291k
日期:2005.10.1
report, we outline a highly enantio- and diastereoselective one-pot method for the efficient synthesis of synthetically useful acyclic epoxy alcohols and allylic epoxy alcohols. Our method takes advantage of a highly enantioselective C-C bond-forming reaction to set the initial chirality. The resulting allyliczinc alkoxide intermediate is then epoxidized in situ using either dioxygen or TBHP in the
在本报告中,我们概述了一种高度对映和非对映选择性的一锅法,用于有效合成合成有用的无环环氧醇和烯丙基环氧醇。我们的方法利用高度对映选择性的 CC 键形成反应来设置初始手性。然后在四烷氧基钛的存在下使用双氧或TBHP将所得烯丙基烷氧基锌中间体原位环氧化。具有多达三个连续立体中心的环氧醇在一锅中形成,具有出色的对映选择性和非对映选择性。在锌醇盐中间体包含两种不同的烯丙基烯烃的情况下,更富电子的双键被化学选择性环氧化以提供烯丙基环氧醇。这种方法代表了一种高效、立体选择性、
Reactivity, Chemoselectivity, and Diastereoselectivity of the Oxyfunctionalization of Chiral Allylic Alcohols and Derivatives in Microemulsions: Comparison of the Chemical Oxidation by the Hydrogen Peroxide/Sodium Molybdate System with the Photooxygenation
作者:Véronique Nardello、Laurent Caron、Jean-Marie Aubry、Sabine Bouttemy、Thomas Wirth、R. Saha-Möller Chantu、Waldemar Adam
DOI:10.1021/ja048589f
日期:2004.9.1
The chiral allylic alcohols 1a-d and their acetate (1e) and silyl ether (1f) derivatives have been oxidized by the H2O2/MoO4(2)- system, a convenient and efficient chemical source of singletoxygen. This chemical peroxidation (formation of the allylic hydroperoxides 2) has been conducted in various media, which include aqueous solutions, organic solvents, and microemulsions. The reactivity, chemoselectivity
手性烯丙醇 1a-d 及其乙酸酯 (1e) 和甲硅烷基醚 (1f) 衍生物已被 H2O2/MoO4(2)- 系统氧化,这是一种方便有效的单线态氧化学来源。这种化学过氧化(烯丙基氢过氧化物 2 的形成)已在各种介质中进行,包括水溶液、有机溶剂和微乳液。将这种化学氧化的反应性、化学选择性和非对映选择性与敏化光氧化的反应性、化学选择性和非对映选择性进行了比较,重点是在微乳液介质中的制备应用。虽然对于两种过氧化模式观察到相似的苏式非对映选择性,但化学选择性显着不同,因为在 / (2)- 系统的化学氧化中,中间过钼酸盐的不良环氧化与原位生成的单线态氧的理想过氧化有效竞争。A proper choice of the type of microemulsion and the reaction conditions furnishes a high chemoselectivity (up
Asymmetric epoxidation of allylic alcohol by the modified sharpless reagent