在氯化锂和新戊酸镁(Mg(OCO t Bu)2)在THF中存在的情况下,用锌粉处理各种烯丙基氯化物或溴化物,可得到烯丙基锌试剂,该溶剂蒸发后,生成的固态锌试剂显示出优异的热稳定性。这些烯丙基试剂与PEPPSI-IPent进行Pd催化的交叉偶联反应,以及对芳基酮和醛进行高度区域选择性和非对映选择性的加成。酰化与各种酰氯区域选择性地产生相应的高烯丙基酮,用新的C C键总是被形成在烯丙基系统的最受阻碳。
Singlet Oxygen Photo-Oxygenation in Water/Pluronic F-127 Hydrogels: Increased Reaction Efficiency Coupled with a Switch in Regioselectivity
作者:Axel G. Griesbeck、Johannes Uhlig、Thomas Sottmann、Lhoussaine Belkoura、Reinhard Strey
DOI:10.1002/chem.201202296
日期:2012.12.7
efficient microenvironments for photochemical reactions, as demonstrated for singletoxygen reactions of monoalkenes. Nonpolar substrates are localized in the nanosized polymer compartment, which can be visualized by neutron scattering. The efficiency of 1O2 reactions is strongly increased for tiglate derivatives and the regioselectivity of the ene reaction of trisubstituted alkenes is completely switched
Pluronic F-127水凝胶是光化学反应的高效微环境,正如单烯烃的单线态氧反应所证明的那样。非极性基质位于纳米级聚合物隔室中,可以通过中子散射将其可视化。tiglate衍生物的1 O 2反应效率大大提高,与溶液相相比,三取代烯烃的烯反应的区域选择性完全切换,与沸石内光氧合相比,其区域选择性完全反转。
Introduction of Allyl and Prenyl Side-Chains into Aromatic Systems by Suzuki Cross-Coupling Reactions
作者:Darío C. Gerbino、Sandra D. Mandolesi、Hans-Günther Schmalz、Julio C. Podestá
DOI:10.1002/ejoc.200900234
日期:2009.8
for the synthesis of allyl- and prenylaromatic compounds. The first part deals with the preparation of boron reagents like arylboronic acids and their pinacol esters as well as of pinacol allyl- and prenylboronates. The second part of the paper is devoted to the use of these boron reagents in Suzuki–Miyaura cross-coupling reactions leading to allylation and prenylation of aromatic compounds. Of the
An efficient dehydrogenative Diels–Alderreaction of prenyl derivatives with dienophiles has been developed. The reaction exhibits broad substrate scope and provides efficient access to cyclohexene derivatives with good to excellent yields. A reasonable mechanism involving a metal-free thermal reversible process is proposed.
A metal‐free dehydrogenative Diels‐Alderreaction of substituted alkenes for the synthesis of tetrahydroisoindolinones has been exploited for the first time. This new method features functional group tolerance and broad substrate scope, providing an efficient access to biologically active tetrahydroisoindolinone skeletons with endo steroselectivity in good to excellent yields.
A copper(I)/DDQ-mediated double-dehydrogenative Diels–Alder (DDDA) reaction of simple butenes with 1,4-diketones and indolones has been established for the first time. This strategy is based on a tandem double-dehydrogenation/Diels–Alderreaction from nonprefunctionalized starting materials, in which both a diene and dienophile were in situgenerated via activation of fourfold inert C(sp3)–H bonds