Fast-Initiating, Ruthenium-based Catalysts for Improved Activity in Highly <i>E</i>-Selective Cross Metathesis
作者:Tonia S. Ahmed、Robert H. Grubbs
DOI:10.1021/jacs.6b11330
日期:2017.2.1
Ruthenium-based olefinmetathesis catalysts bearing dithiolate ligands have been recently employed to generate olefins with high E-selectivity (>99% E) but have been limited by low to moderate yields. In this report, 1H NMR studies reveal that a major contributingfactor to this low activity is the extremely low initiation rates of these catalysts with trans olefins. Introducing a 2-isopropoxy-3-phenylbenzylidene
High <i>Trans</i> Kinetic Selectivity in Ruthenium-Based Olefin Cross-Metathesis through Stereoretention
作者:Adam M. Johns、Tonia S. Ahmed、Bradford W. Jackson、Robert H. Grubbs、Richard L. Pederson
DOI:10.1021/acs.orglett.6b00031
日期:2016.2.19
controlled, highly trans-selective (>98%) olefin cross-metathesis reaction is demonstrated using Ru-based catalysts. Reactions with either trans or cis olefins afford products with highly trans or cis stereochemistry, respectively. This E-selective olefin cross-metathesis is shown to occur between two trans olefins and between a trans olefin and a terminal olefin. Additionally, new stereoretentive catalysts
[EN] OLEFIN METATHESIS CATALYSTS<br/>[FR] CATALYSEURS DE MÉTATHÈSE D'OLÉFINES
申请人:MATERIA INC
公开号:WO2017100585A1
公开(公告)日:2017-06-15
This invention relates generally to metathesis catalysts and the use of such catalysts in the metathesis of olefins and olefin compounds, more particularly, in the use of such catalysts in Z and E selective olefin metathesis reactions. The invention has utility in the fields of organometallics and organic synthesis.
Regioselective Carbon-Carbon Bond Formation in Titanium Mediated Reaction of Ethylmagnesium Bromide with Allylic Alcohols and Allylic Ethers
作者:Oleg G. Kulinkovich、Oleg L. Epstein、Vladimir E. Isakov、Ekaterina A. Khmel'nitskaya
DOI:10.1055/s-2001-9707
日期:——
In the presence of Ti(Oi-Pr)4 reaction of EtMgBr with allylic alcohols and allylicethers affords the products of formal SN2′ substitution of hydroxy or alkoxy groups with ethyl groups in moderate to good yields and excellent regioselectivity. The mechanism of the reaction includes the formation of titanacyclopropanes as the key organometallic intermediates. Promoting action of EtMgBr on the process
Tergal Gland Secretion of the Rove Beetle
<i>Aleochara pseudochrysorrhoa</i>
(Staphylinidae: Aleocharinae): Chemical Composition and Biological Roles
作者:Maycon R. Silva、Diogo M. Vidal、Leonardo Figueiredo、Pamela T. Bandeira、Jan Bergmann、Paulo H. G. Zarbin
DOI:10.1002/cbdv.202000483
日期:2020.10
Aleocharapseudochrysorrhoa has a glandular complex known as the tergalgland. Generally, the tergalglandsecretion (TGS) has been described to have defensive function, but some reports point to a possible secondary function of this complex. For example, the TGS of the related species A. curtula has been demonstrated to possess an important role in intraspecies communication. In this work, we describe