Rhenium-Catalyzed 1,3-Isomerization of Allylic Alcohols: Scope and Chirality Transfer
作者:Christie Morrill、Gregory L. Beutner、Robert H. Grubbs
DOI:10.1021/jo061436l
日期:2006.9.1
The scope of the triphenylsilyl perrhennate (O3ReOSiPh3, 1) catalyzed 1,3-isomerization of allylicalcohols has been thoroughly explored. It was found to be effective for a wide variety of secondary and tertiary allylicalcohol substrates bearing aryl, alkyl, and cyano substituents. Two general reaction types were found which gave high levels of product selectivity: those driven by formation of an
LuCl3 reacts with t-butyllithium in the presence of ether and tetramethylethylene diamine (tmed) to form [Li(tmed)2][Lu(t-C4H9)4], the structure of which has been elucidated through complete X-ray analysis. The crystals are orthorhombic with a 20.995(9), b 18.310(7), c 9.527(2) Å, space group P21ab, Z = 4, D(calcd) 1.17 g cm−3, R = 0.035, and 2471 observed reflections. The compound undergoes 1,2-addition
LuCl 3在醚和四甲基乙二胺(tmed)的存在下与叔丁基锂反应形成[Li(tmed)2 ] [Lu(tC 4 H 9)4 ],其结构已通过完整的X射线阐明分析。晶体是正交晶体,具有20.995(9),b 18.310(7),c 9.527(2)Å,空间群P 2 1 ab,Z = 4,D(计算)1.17 g cm -3,R= 0.035,观察到2471个反射。该化合物分别在肉桂醛,苯并丙酮,1-苯基丁烯-2-甲基-3-酮,2-甲基丁烯-3-酮和环己酮上进行1,2-加成,以在水解反应混合物后得到α-t-丁基取代的烯醇。通过GC / MS方法鉴定反应产物。
The use of a [4 + 2] cycloaddition reaction for the preparation of a series of ‘tethered’ Ru(<scp>ii</scp>)–diamine and aminoalcohol complexes
作者:Fung Kei Cheung、Aidan M. Hayes、David J. Morris、Martin Wills
DOI:10.1039/b700744b
日期:——
A series of catalysts have been prepared for use in the asymmetric transfer hydrogenation of ketones. The complexes were prepared using a [4 + 2] cycloaddition reaction at a key step in the reaction sequence. This provides a means for the synthesis of catalysts with modifications at specific sites.
Stereoselective Dehydroxyboration of Allylic Alcohols to Access (<i>E</i>)-Allylboronates by a Combination of C–OH Cleavage and Boron Transfer under Iron Catalysis
Iron-catalyzed direct SN2′ dehydroxyboration of allylic alcohols has been developed to access (E)-stereoselective allylboronates. Allylic alcohols with diverse structures and functional groups, especially derived from natural products, underwent smooth transformation. The six-membered ring transition state formed by allylic alcohols and iron–boron intermediate was indicated to be the key component
铁催化的烯丙醇直接 S N 2' 脱羟基硼酸已被开发用于获得 ( E )-立体选择性烯丙基硼酸酯。具有多种结构和官能团的烯丙醇,特别是来自天然产物的烯丙醇,经历了平稳的转变。由烯丙醇和铁-硼中间体形成的六元环过渡态被证明是参与硼基团转移、C-OH键活化和立体选择性控制的关键成分。
Highly Selective 1,3-Isomerization of Allylic Alcohols via Rhenium Oxo Catalysis
作者:Christie Morrill、Robert H. Grubbs
DOI:10.1021/ja044054a
日期:2005.3.9
strategies are developed to promote the highlyselective 1,3-isomerization of a variety of allylic alcohols using O3ReOSiPh3 as a catalyst. The first strategy utilizes substrates whose 1,3-regioisomer contains a conjugated alkene, which relies on thermodynamics to obtain high selectivity. The second strategy employs N,O-bis(trimethylsilyl)acetamide as an additive to selectively and irreversibly remove the product