作者:Ashok K. Basak、Naoyuki Shimada、William F. Bow、David A. Vicic、Marcus A. Tius
DOI:10.1021/ja103028r
日期:2010.6.23
An organocatalytic asymmetric Nazarov cyclization of diketoesters that proceeds by means of a dual activation mechanism has been developed. Screening of a number of catalysts led to a new thiourea that incorporates a primary amino group. The method gives rise to cyclic products with two adjacent quaternaryasymmetriccarbon atoms, one of which is an all-carbon stereocenter, with complete or nearly
Traceless sulfone linker cleavage triggered by ozonolysis: solid-phase synthesis of diverse α-β-unsaturated carbonyl compounds
作者:Yi-Fan Chang、Yi-Rui Jiang、Wei-Chieh Cheng
DOI:10.1016/j.tetlet.2007.11.064
日期:2008.1
The highly efficient and convenient protocol to prepare diverse α,β-unsaturated aldehydes, ketones, and acids via the parallel solid-phase synthesis is developed. The key sulfone linker cleavage strategy is performed by ozonolysis to generate a carbonyl moiety followed by base-mediated polymer-bound sulfinate elimination to release our desired molecules from the resin. All α,β-unsaturated carbonyl compounds
A facile access to indene frameworks through condensation of substituted cinnamylaldehydes and sulfonylamines under the catalysis of FeCl3 is reported.
Neutral Nazarov-Type Cyclization Catalyzed by Palladium(0)
作者:Naoyuki Shimada、Craig Stewart、William F. Bow、Anais Jolit、Kahoano Wong、Zhe Zhou、Marcus A. Tius
DOI:10.1002/anie.201201724
日期:2012.6.4
Joining the circle: The first Pd0 catalyzed Nazarov‐type cyclization of diketoesters (see scheme) proceeds in 70 % to 95 % yield under strictly neutral pH conditions. Aryl substitution of the diketoesters is not required, so the reaction shows great versatility and can also proceed with aliphatic substrates.
Reaction of allyl and benzyl alcohols, and their toluene-p-sulphonates, with furan
作者:P. H. Boyle、J. H. Coy、H. N. Dobbs
DOI:10.1039/p19720001617
日期:——
furan in acetonitrile. The reaction is catalysed by lithium perchlorate. Some alcohols can react directly with furan under acidic conditions. Alcohols investigated include 2-benzylallyl alcohol (8), E-α-methylcinnamyl alcohol (2) and its p-nitro- and p-methoxy-derivatives, (1) and (3), benzyl alcohol, p-nitrobenzyl alcohol, and p-methoxybenzyl alcohol. Both geometricalisomers of α-methyl-p-nitrocinnamyl