Ligand-controlled iridium-catalyzed semihydrogenation of alkynes with ethanol: highly stereoselective synthesis of <i>E</i>- and <i>Z</i>-alkenes
作者:Jinfei Yang、Chengniu Wang、Yufeng Sun、Xuyan Man、Jinxia Li、Fei Sun
DOI:10.1039/c8cc09714c
日期:——
iridium-catalyzed semihydrogenation of alkynes to E- and Z-alkenes with ethanol was developed. Effective selectivity control was achieved by ligand regulation. The use of 1,2-bis(diphenylphosphino)ethane (DPPE) and 1,5-cyclooctadiene (COD) was critical for the stereoselective semihydrogenation of alkynes. The general applicability of this procedure was highlighted by the synthesis of more than 40 alkenes, with
<i>N</i>-Methylphenothiazine <i>S</i>-Oxide Enabled Oxidative C(sp<sup>2</sup>)–C(sp<sup>2</sup>) Coupling of Boronic Acids with Organolithiums via Phenothiaziniums
we report the development of a transition-metal-free oxidative C(sp2)–C(sp2) coupling of readily available boronic acids and organolithiums via phenothiazinium ions. Various biaryl, styrene, and diene derivatives were obtained using this reaction system. The key to this process is N-methylphenothiazine S-oxide (PTZSO), which allows efficient conversion of boronic acids to phenothiazinium ions. The mechanism
Novel Carbazole‐Based<i>N</i>‐Heterocyclic Carbene Ligands to Access Synthetically Relevant Stilbenes in Pd‐Catalyzed Coupling Processes
作者:Tejpalsingh Ramsingh Girase、Anant R. Kapdi
DOI:10.1002/asia.201900419
日期:2019.8
A series of new carbazole‐based N‐heterocyclic carbene (NHC) ligands have been synthesized in a simple and facile synthetic route and subsequently used in a Pd/carbazole‐based NHC catalytic system, which was found to be effective in catalyzing Heck reactions to provide substituted stilbene derivatives in good yields. Several bioactive stilbenes, including pterostilbene, pinosylvin, trimethoxy resveratrol
<i>E</i>,<i>Z</i>-Selectivity in the reductive cross-coupling of two benzaldehydes to stilbenes under substrate control
作者:Nicolas D'Imperio、Anna I. Arkhypchuk、Sascha Ott
DOI:10.1039/d0ob01139h
日期:——
on the order of addition of the two coupling partners, the same olefin can be produced in either E- or Z-enriched form under identical reaction conditions. A systematic study of the correlation between the stereochemical outcome of the reaction and the substitution pattern at the two aldehydes is presented. The results can be used as guidelines to predict the product stereochemistry.
Heck–Matsuda reaction of arenediazonium salts in water
作者:Jordi Salabert、Rosa María Sebastián、Adelina Vallribera、José Francisco Cívicos、Carmen Nájera
DOI:10.1016/j.tet.2013.01.049
日期:2013.3
The palladium-catalyzed arylation of alkenes with aryldiazonium salts can be carried out through an environmentally friendly protocol using neat water low palladium loadings at room temperature under base-additive- and ligand-free conditions.