Structurally Defined Molecular Hypervalent Iodine Catalysts for Intermolecular Enantioselective Reactions
作者:Stefan Haubenreisser、Thorsten H. Wöste、Claudio Martínez、Kazuaki Ishihara、Kilian Muñiz
DOI:10.1002/anie.201507180
日期:2016.1.4
Molecular structures of the most prominent chiral non‐racemic hypervalent iodine(III) reagents to date have been elucidated for the first time. The formation of a chirally induced supramolecular scaffold based on a selective hydrogen‐bonding arrangement provides an explanation for the consistently high asymmetric induction with these reagents. As an exploratory example, their scope as chiral catalysts
Asymmetric Diboration of Terminal Alkenes with a Rhodium Catalyst and Subsequent Oxidation: Enantioselective Synthesis of Optically Active 1,2-Diols
作者:Kenji Toribatake、Hisao Nishiyama
DOI:10.1002/anie.201305181
日期:2013.10.11
Pin it down: A highly enantioselective diboration of terminal alkenes with chiral 1 and bis(pinacolato)diboron (B2pin2) was realized. Subsequent oxidation of the diboron adducts with sodium peroxoborate readily gave the corresponding opticallyactive 1,2‐diols in high yields and high enantioselectivities.
Enantioselective hydrolysis of various substituted styrene oxides with Aspergillus Niger CGMCC 0496Electronic supplementary information (ESI) available: experimental details. See http://www.rsc.org/suppdata/ob/b3/b312469j/
作者:Hao Jin、Zu-yi Li、Xiao-Wei Dong
DOI:10.1039/b312469j
日期:——
Enantioselective biohydrolysis of various substituted styrene oxides using whole fungus cells of Aspergillus nigerCGMCC 0496 are described. The results show not only para- but also some ortho- substituted styrene oxides can achieve high enantioselectivity during the hydrolysis.
Enantioselective Vicinal Diacetoxylation of Alkenes under Chiral Iodine(III) Catalysis
作者:Kilian Muñiz、Thorsten Wöste
DOI:10.1055/s-0035-1561313
日期:——
corresponding vicinal diacetoxylation products with up to 96% ee. A procedure for the intermolecular enantioselective dioxygenation of alkenes under iodine(III) catalysis has been developed. This protocol employs Selectfluor as the terminal oxidant together with a defined C 2-symmetric aryl iodide as the organocatalyst. This enantioselective reaction proceeds under mild conditions and converts a series of
coupling method, to assign the absoluteconfiguration of the benzylic stereogenic center of 1-aryl-1,2-diols. According to this method, it is only necessary to prepare the 4-biphenylboronic esters of the diols and to record their CDspectra in the 230−300 nm range, i.e., in the range corresponding to the long-axis 1La transition of the biphenyl chromophore. From the sign of the CD couplet or Cotton effect
我们在此基于激子偶联方法描述一种简单,通用且可靠的非经验方法,以分配1-芳基-1,2-二醇的苄基立体异构中心的绝对构型。根据该方法,仅需制备二醇的4-联苯硼酸酯并记录其在230-300 nm范围内(即在对应于长轴1 L a的范围内)的CD光谱联苯发色团的过渡。从260 nm处的CD偶联或棉花效应的征兆,可以知道由芳基和联苯发色团跃迁定义的手性,然后确定苄基碳的绝对构型。通过这种方法,已经制定了简单的规则,使我们能够建立许多种类的1-芳基-1,2-二醇的绝对构型。