Methanesulfonamide: a Cosolvent and a General Acid Catalyst in Sharpless Asymmetric Dihydroxylations
作者:Mikko H. Junttila、Osmo O. E. Hormi
DOI:10.1021/jo8026998
日期:2009.4.17
effect on the reaction time and methanesulfonamide effect. The more polar the intermediate osmate ester, the faster is the reaction without methanesulfonamide and the smaller the accelerating methanesulfonamide effect. Methanesulfonamide had no accelerating effect in the asymmetric dihydroxylation of short chain terminal aliphatic olefins as a result of easier accessibility of terminal osmate ester
Osmium-Catalyzed Dihydroxylation of Olefins Using Dioxygen or Air as the Terminal Oxidant
作者:Christian Döbler、Gerald M. Mehltretter、Uta Sundermeier、Matthias Beller
DOI:10.1021/ja000802u
日期:2000.10.1
The osmium-catalyzed dihydroxylation of various olefinsusing molecular oxygen or air as the stoichiometric oxidant is reported. Aromatic olefins yield the corresponding diols in good to excellent chemoselectivities under optimized pH conditions (pH = 10.4−12.0). Air can be used under moderate pressures (3−9 bar) instead of dioxygen as the reoxidant. By increasing the oxygen content of the solution
Asymmetric oxidation of olefins to vicinal diols with osmium tetroxide
作者:Maritherese Tokles、John K. Snyder
DOI:10.1016/s0040-4039(00)84881-9
日期:1986.1
High levels of asymmetry can be achieved in the osmium tetroxide cis-hydroxylation of olefins by employing (−)-(R,R)-N,N,N′,N′-tetramethylcyclohexane-1,2-trans-diamine as a chiral ligand for the osmium.
Catalytic asymmetric dihydroxylation of olefins using a recoverable and reusable OsO<sub>4</sub><sup>2−</sup>in ionic liquid [bmim][PF<sub>6</sub>]
作者:Luís C. Branco、Carlos A. M. Afonso
DOI:10.1039/b208631j
日期:——
The use of the solvent systems water/ionicliquid or water/ionicliquid/tert-butanol provides a recoverable, reusable, robust and simple system for the asymmetric dihydroxylation of olefins, based on the immobilization of the osmium-ligand catalyst in the ionicliquid phase.
Sodium Chlorite as an Efficient Oxidant and Hydroxy Ion Pump in Osmium-Catalyzed Asymmetric Dihydroxylation
作者:Mikko H. Junttila、Osmo E. O. Hormi
DOI:10.1021/jo0496749
日期:2004.7.1
Sodium chlorite is an efficient stoichiometric oxidant in Sharpless asymmetricdihydroxylation. One sodium chlorite provides the reaction with the stoichiometric number of electrons and hydroxide ions needed to dihydroxylate two olefins without the consumption of any additional base. 100% conversion in sodium chlorite asymmetricdihydroxylation of styrene was achieved twice as fast as in the established
亚氯酸钠是Sharpless不对称二羟基化反应的有效化学计量氧化剂。一种亚氯酸钠为反应提供了化学计量的电子和氢氧根离子,可以使两种烯烃二羟基化,而无需消耗任何额外的碱。在亚氯酸钠中,苯乙烯的100%转化率是已建立的Sharpless K 3 [Fe(CN)6 ]二羟基化速度的两倍。甚至内烯烃也可以在没有水解助剂的情况下用亚氯酸钠快速二羟基化。将八种烯烃二羟基化为相应的邻位二醇,其收率和ee均与文献中其他类似方法所报道的一样。