Enantioselective synthesis of spirocyclic cyclopentenes: asymmetric [3+2] annulation of 2-arylideneindane-1,3-diones with MBH carbonates derivatives catalyzed by multifunctional thiourea–phosphines
作者:Fangle Hu、Yin Wei、Min Shi
DOI:10.1016/j.tet.2012.07.013
日期:2012.9
The [3+2] annulation reactions of 2-arylideneindane-1,3-diones with Morita–Baylis–Hillman (MBH) carbonates proceeded smoothly in the presence of multifunctional thiourea–phosphines to produce the corresponding quaternary carbon centered spirocyclic cyclopentenes in moderate yields, with high diastereoselectivities and enantioselectivities under mild conditions. The plausible reaction has been also
Cooperative Rh(II)/Pd(0) Dual Catalysis: Synthesis of Highly Substituted 3(2<i>H</i>)-Furanones with a C2-Quaternary Center via a Cyclization/Allylic Alkylation Cascade of α-Diazo-δ-keto-esters
cyclization/allylic alkylation cascade of stable α-diazo-δ-keto-esters has been developed. Highly substituted 3(2H)-furanones with a C2-quaternary center can be obtained efficiently under mild conditions via one-pot synthesis. Remarkably, this binary catalytic system shows high chemo-, regio-, and stereoselectivity and excellent tolerance to various functionalities.
In this paper, phosphine‐catalyzed [3 + 3] annulation of Morita–Baylis–Hillman carbonates with C,N‐cyclic azomethine imines has been achieved. The reaction worked smoothly under mild conditions to afford 4,6,7,11b‐tetrahydro‐1H‐pyridazino[6,1‐a]isoquinoline derivatives in high yields with good to excellent diastereoselectivities.
A silver/palladium relay catalyzed 1,3-dipole annulation/allylation reaction of iminoesters and Baylis-Hillman acetates for the construction of fully substituted allyl imidazolidines is reported. The reaction of both iminoesters and Baylis-Hillman acetates affords the fully substituted allyl imidazolidines in high yields and regioselectivities. The three component reaction is triggered by silver-catalyzed
Highly efficient one-pot synthesis of fused pyrimidones from 2-heteroaryl amines and Morita–Baylis–Hillman carbonates<i>via</i>intermolecular cyclocondensation
highly selective and efficient cyclocondensation reaction for construction of various 3-substituted-2H-pyrido[1,2-a]pyrimidin-2-ones and related fused pyrimidones from allylic carbonates and 2-heteroaryl amines has been developed. The transformation involves one-pot sequential aza-Michael addition, intramolecular acyl substitution, and [1,3]-H shift. The method is catalyst free, eco-friendly, scalable, and