Polymer-supported selenium-induced electrophilic cyclization: solid-phase synthesis of poly-substituted dihydrofurans and tetrahydrofurans
摘要:
Poly-substituted dihydrofurans and tetrahydrofurans have been synthesized through polymer-supported selenium-induced intramolecular electrophilic cyclization, followed by selenoxide syn-elimination or novel nucleophilic substitution cleavage of selenium resin with good yields and purities. (C) 2004 Elsevier Ltd. All rights reserved.
A theoretical study on the carbocationic reactivity of 2-fluoroallylic alcohols and derivatives explains some experimental findings. An outline is also given of synthetic approaches towards fluoroallylic amines and more complex carbon skeletons starting with fluoroallylic alcohols.
Copper(I) promoted CC bond forming reactions: direct activation of allyl alcohols
作者:Jubaraj.B. Baruah、Ashoka G. Samuelson
DOI:10.1016/0022-328x(89)87015-9
日期:1989.2
Allylic alcohols, acetates, carbonates and chlorides can be activated by copper(I) salts towards nucleophilic substitution by carbon nucleophiles under relatively mild conditions.
Palladium-catalyzed desulfinylative C–C allylation of Grignard reagents and enolates using allylsulfonyl chlorides and esters
作者:Chandra M. Rao Volla、Srinivas Reddy Dubbaka、Pierre Vogel
DOI:10.1016/j.tet.2008.11.007
日期:2009.1
(E)-but-2-enesulfonyl chlorides have been used as electrophilic partners in desulfinylative palladium-catalyzed C–C coupling with Grignardreagents and sodium salts of dimethyl malonate and methyl acetoacetate. Neopentyl alk-2-ene sulfonates can also be used as electrophilic partners in desulfinylative allylic arylations and allylic alkylations. The regioselectivity of the allylic arylation and alkylation depends
An Intramolecular Prins Double Cyclization Catalyzed by Silyl Triflates<sup>1</sup>
作者:Michael E. Jung、Steve Angelica、Derin C. D'Amico
DOI:10.1021/jo971337v
日期:1997.12.1
Several intramolecular Prins double cyclizations are reported. The 2-alkyl 5-hepten-1,2-diols and their analogues, 9-11, were prepared and oxidized to the aldehydes 6-8 under Swern conditions. Treatment of these alpha-hydroxy aldehydes with TBSOTf and a hindered base gave the products of an intramolecular Prins double cyclization, namely the 7-(silyloxy)-2-oxabicyclo[2.2.1]heptanes, 17-19, in 84-92% yield. These compounds were formed as single diastereomers with only the anti silyl ethers being obtained. The cyclizations occur when five-membered rings are being formed and when the initially formed cation is highly stabilized. Other substrates do not cyclize, e.g., when the alpha-hydroxy aldehydes 20-22, prepared from 26-28, are treated under similar conditions, none of the corresponding cyclization products, 23-25, were obtained.
Effective activation of allylic etherrs by boron oxide in palladium catalyzed allylic alkylation
作者:Xiyan Lu、Xiaohui Jiang
DOI:10.1016/0022-328x(89)85259-3
日期:1989.1
KUROSAWA HIDEO, J. CHEM. SOC. DALTON TRANS., 1979, NO 6, 939-943