Multi-Component Regio- and Diastereoselective Cobalt-catalyzed Hydrovinylation/Allylboration Reaction Sequence
摘要:
The combination of a regloselective cobalt-catalyzed 1,4-hydrovinylation and the dlastereoselective allyiboronation reaction leads to a wide scope of functionalized hydroxydienyl esters In a one-pot reaction in excellent yields. With catalytic amounts of base, these products are easily converted either into alpha,beta,gamma,delta-unsaturated hydroxyl esters or complex tetrasubstituted tetrahydropyrans In chemo- and diastereoselective fashions. In addition, a high-yielding four-component one-pot reaction involving an acrylate, two different and unsymmetrical 1,3-dienes, and an unsaturated aldehyde Is presented.
Herein we disclose an asymmetric allylation of 3-hydroxyisobenzofuran-1(3H)-ones with boron allylation reagents to construct chiral phthalide derivatives. The simple Bi(OAc)3/chiral phosphoricacid catalytic system proves to be efficient in this method, delivering the desired chiral 3-allylisobenzofuran-1(3H)-ones in good yields (up to 99%) and high enantioselectivities (up to 99.5:0.5 e.r.) under mild
作者:Liu Cai、Yu-Liang Pan、Li Chen、Jin-Pei Cheng、Xin Li
DOI:10.1039/d0cc05855f
日期:——
An efficient asymmetric allylation reaction of allylboronates with seven-membered cyclic imines, dibenzo[b,f][1,4]oxazepines, is described. The reaction, which is catalyzed by a Bi(OAc)3/CPA system, gives a range of chiral nitrogen-containing heterocycle structures in high yields and with good enantioselectivities. The conversion of these products to nitrogen-containing heterocycles is also demonstrated
The BINOL‐derived chiral phosphoric acid (R)‐TRIP is utilized as an organocatalyst in the asymmetric isoprenylboration reaction of aldehydes, wherein hydrogen‐bond interactions play a key role in the control of enantioselectivity. A wide arrays of enantioenriched dienyl homoallyl alcohols, including two natural products (−)‐Ipsdienol and (−)‐Ipsenol, have been successfully constituted. The synthetic
Double- and Triple-Cobalt Catalysis in Multicomponent Reactions
作者:Florian Erver、Gerhard Hilt
DOI:10.1021/ol300504f
日期:2012.4.6
different types of cobalt-catalyzed transformations in one-pot procedures is described. One of the key building blocks, a boron-functionalized isoprene derivative (boroprene), led to the realization of four-component reaction sequences comprising the cobalt-catalyzed Diels–Alder and a 1,4-hydrovinylation reaction. Eventually, a reaction sequence including a cobalt-catalyzed Diels–Alder reaction, a cobalt-catalyzed
The Petasisreaction using (1S,2R)-1-amino-2-indanol as the substrate and an activator to construct α- and β-butadienyl amines in optically pure forms was realized, which are otherwise difficult to prepare. The reactions feature a metal-free nature, broad substrate scope, complete regioselectivities (γ-selectivity of pinacol homoallenyl- and isoprenylboronates), and high to excellent chirality induction