Switchable Synthetic Strategy toward Trisubstituted and Tetrasubstituted Exocyclic Alkenes
摘要:
An efficient and facile method for the construction of tri- or tetrasubstituted exocyclic alkenes is achieved via a Cu(I)-catalytic system. This protocol exhibits mild conditions, low-cost catalyst, good functional group tolerance, and good yields. The selectivity toward tri- or tetrasubstituted alkenes can be delicately controlled by adjustment of base and solvent. A preliminary mechanism study manifested that the reaction undergoes a radical process, where B(2)pin(2) plays an indispensable role.
Aryltriolborates as Air- and Water-Stable Bases for Wittig Olefination
作者:Wenhua Huang、Shuang-Hong Zhao、Ning Xu
DOI:10.1055/s-0034-1378919
日期:——
1-tris(hydroxymethyl)ethane, and aqueous tetrabutylammonium hydroxide. The aryltriolborates can be used as bases in Wittigreactions of aromatic aldehydes with all three types of phosphorus ylides: stabilized and semistabilized ylides can be generated at room temperature, and nonstabilizedylides at 120 °C (bath temperature). Tetrabutylammonium aryltriolborates have been synthesized in 37–66% yield by a one-pot
Palladium-Catalyzed Alkyne Insertion/Reduction Route to Trisubstituted Olefins
作者:Erin R. Fruchey、Brendan M. Monks、Andrea M. Patterson、Silas P. Cook
DOI:10.1021/ol4018694
日期:2013.9.6
A new route to trisubstitutedolefins through a palladium-catalyzed alkyne insertion/reduction reaction with unactivated alkyl iodides is reported. The reaction proceeds under mild conditions and tolerates a range of functional groups and substitution patterns. Preliminary mechanistic inquiry suggests that the transformation may proceed through a hybrid radical/organometallic pathway.
Palladium-Catalyzed Alkyne Insertion/Suzuki Reaction of Alkyl Iodides
作者:Brendan M. Monks、Silas P. Cook
DOI:10.1021/ja307761f
日期:2012.9.19
A palladium-catalyzed alkyne insertion/Suzuki reaction with unactivated alkyliodides is described. Under the reaction conditions, selective migratory insertion of alkynes avoids β-hydride elimination and provides a facile synthesis of stereodefined, tetrasubstituted olefins. The transformation offers broad substrate scope for both the alkyliodide and boron nucleophile. Mechanistic studies have revealed
Consecutive visible-light photoredox decarboxylative couplings of adipic acid active esters with alkynyl sulfones leading to cyclic compounds
作者:Jingjing Li、Hua Tian、Min Jiang、Haijun Yang、Yufen Zhao、Hua Fu
DOI:10.1039/c6cc04386k
日期:——
active esters (bis(1,3-dioxoisoindolin-2-yl)-substituted hexanedioates) with substituted 1-(2-arylethynylsulfonyl)benzenes have been developed under visible-light photocatalysis. The successive photoredox decarboxylative C-Cbondformation...
Silver‐Catalysed Hydroarylation of Highly Substituted Styrenes
作者:Toryn Dalton、Steffen Greßies、Mowpriya Das、Maximilian Niehues、Malte L. Schrader、Christian Gutheil、Bart Jan Ravoo、Frank Glorius
DOI:10.1002/anie.202016268
日期:2021.4.6
Hydroarylation is an effective strategy to rapidly increase the complexity of organic structures by transforming flat alkene moieties into three‐dimensional frameworks. Many strategies have already been developed to achieve the hydroarylation of styrenes, however most of these reports examine the hydroarylation of unpolar, β‐mono‐ or β‐unsubstituted styrenes, while exploring mainly electron‐rich benzene