119235-89-1Relevant articles and documents
Method for the dihydroxylation of olefins using transition metal catalysts
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Page column 8, (2008/06/13)
This invention relates to process for dihydroxylation of olefins using transition metal catalysts to obtain monofunctional, bifunctional, and/or polyfunctional 1,2-diols of the formula (I) R1R2C(OH)—C(OH)R3R4??(I) where R1to R4are defined herein, by reacting an olefin of the formula (II) R1R2C═CR3R4??(II) where R1to R4are defined as for formula (I), with molecular oxygen in the presence of an osmium, ruthenium, or manganese compound in water or a water-containing solvent mixture at a pH of from 7.5 to 13.
Osmium-Catalyzed Dihydroxylation of Olefins Using Dioxygen or Air as the Terminal Oxidant
Doebler, Christian,Mehltretter, Gerald M.,Sundermeier, Uta,Beller, Matthias
, p. 10289 - 10289 (2007/10/03)
The osmium-catalyzed dihydroxylation of various olefins using 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, it is possible to achieve highly efficient conversion at low catalyst amount (catalyst/substrate = 1:4000). Tri- and tetrasubstituted olefins are oxidized at pH > 11 to give the corresponding 1,2-diols in good to very good yields without requiring the addition of sulfonamides or other hydrolysis agents. Studies of the dihydroxylation of functionalized olefins demonstrate that the reaction conditions tolerate a variety of functional groups. In the presence of dihydroquinine or dihydroquinidine derivatives (Sharpless ligands), asymmetric dihydroxylations occur with lower enantioselectivities than tose of the classical K3[Fe(CN)6] reoxidation system.
The protection of ketones and aldehydes as 4-trimethylsilylmethyl-1,3- dioxolanes
Lillie,Avery
, p. 969 - 972 (2007/10/02)
The 1,3-dioxolanation of carbonyl compounds with 2,3- bis(trimethylsilyloxy)-trimethylsilylpropane (BTTP) in the presence of catalytic amounts of trimethylsilyl trifluoromethanesulfonate (TMSOTf) has been investigated. BTTP readily converted unhindered ketones and aldehydes to their corresponding 4-trimethylsilylmethyl-1,3-dioxolanes, but failed for more hindered substrates. The 4-trimethylsilylmethyl-1,3-dioxolane can be selectively cleaved to regenerate the carbonyl compound in the presence of a 1,3-dioxolane using either LiBF4 or HF in acetonitrile.
Synthesis of Optically Active Secondary Allylic Alcohols from Allylsilanes via Successive Asymmetric Dihydroxylation (AD) and Peterson Olefination Reaction
Okamoto, Sentaro,Tani, Kousuke,Sato, Fumie,Sharpless, K. Barry,Zargarian, Davit
, p. 2509 - 2512 (2007/10/02)
Optically active, secondary allylic alcohols can be prepared from allylic silanes by the successive asymmetric dihydroxylation and Peterson olefination reactions.The effects of trialkylsilyl groups on the outcome of the AD reaction on vinyl and allyl silanes are also discussed.