Palladacycle-Catalyzed Regioselective Heck Reaction Using Diaryliodonium Triflates and Aryl Iodides
作者:Lu Lei、Pei-Sen Zou、Zhi-Xin Wang、Cui Liang、Cheng Hou、Dong-Liang Mo
DOI:10.1021/acs.orglett.1c04120
日期:2022.1.21
P-containing palladacycle-catalyzed regioselective Heck reaction of 2,3-dihydrofuran with diaryliodonium salts and aryl iodides to afford 2-aryl-2,5-dihydrofurans and 2-aryl-2,3-dihydrofurans, respectively, in good yields. Mechanistic studies revealed that the oxidative addition of diaryliodonium salts to palladacycles to form Pd(IV) species showed high chemoselectivity and that electron-rich aryl moieties
terminal alkenes catalysed by (R,R)-ethylene-1,2-bis(η5-4,5,6,7-tetrahydro-1-indenyl)zirconium(R)-1,1′-binaphth-2,2′-diolate gave low turnovers and enantioexcesses. A novel Ci symmetric zirconocene dichloride CpCp′ZrCl2 (Cp = C5H5, Cp′ = 1-neomenthyl-4,5,6,7-tetrahydroindenyl) was prepared which gave better enantioselectivity, is cheaper to make, catalytically more active, and recoverable.
通过催化末端烯烃的ethylmagnesiation([R ,- [R )-亚乙基-1,2-双(η 5 -4,5,6,7-四氢-1-茚基)合锆([R)-1,1'- binaphth- 2,2'-羟乙酸盐产生较低的营业额和对映体过量。制备了一种新的C i对称的二茂锆锆CpCp'ZrCl 2(Cp = C 5 H 5,Cp'= 1-新薄荷基-4,5,6,7-四氢茚基),该对映体具有更好的对映选择性,制造成本更低,催化作用更多。活跃且可恢复。
(EN) A chiral, organometallic compound which, at a molecular level, has no C2 symmetry and comprises a carbon to carbon bond joining a chiral carbon atom to a carbon atom of a cyclopentadiene ring that is non-symmetrically substituted. Examples of such compounds include compounds of formula (I) wherein, X1 and X2 are, independently, groups which are removable during a chemical reaction; M is titanium, zirconium or hafnium; and R1-8,11 are as specified in the description.(FR) L'invention porte sur un composé organométallique, chiral, qui, à un niveau moléculaire, est asymétrique en C2 et comporte une liaison carbone-carbone liant un atome chiral de carbone à un atome de carbone d'un anneau de cyclopentadiène substitué de manière asymétrique. Au nombre de ces composés figurent des composés de la formule (I) dans laquelle X1 et X2 représentent, de façon indépendante, des groupes remplaçables au cours d'une réaction chimique; M est titane, zirconium ou hafnium et où R1-8,11 correspond à la définition donnée dans la description.
developed as an efficient method for C(sp3)–C(sp3) coupling with broad substrate availability and high functional group compatibility. However, auxiliary groups, a conjugated group or a chelation-directing group, are commonly required to attain high regio- and enantioselectivities. Herein, we reported a ligand-controlled cobalt-hydride-catalyzed regio-, enantio-, and diastereoselective oxyheterocyclic
Chiral Silver Phosphate-Catalyzed Cycloisomeric Kinetic Resolution of α-Allenic Alcohols
作者:Yan Wang、Kuan Zheng、Ran Hong
DOI:10.1021/ja300453u
日期:2012.3.7
A kinetic resolution of a-allenic alcohols is realized through chiral silver phosphate-catalyzed cycloisomerization with high stereoselectivity (selectivity factor up to 189) and tolerance of a variety of functional groups. A mechanistic model is proposed to interpret the origin of the high stereoselectivity and broad substrate scope.