2-Alkenyl dioxolanylium cations, new reactive dienophiles in low temperature asymmetric Diels-Alder reactions
作者:Arnaud Haudrechy、Willy Picoul、Yves Langlois
DOI:10.1016/s0957-4166(96)00470-3
日期:1997.1
orthoesters 14–22 were prepared by an exchange reaction with orthoester 13. These compounds, after treatment with trimethylsilytriflate or tin(IV) chloride, gave rise to vinyl dioxolanylium cations which proved to be very reactive dienophiles in various Diels-Alder reactions.
α-Acetyl- and α-Cyanovinyl 2,4-Dinitrophenyl Carboxylate as Useful Ketene Equivalents for the Diels-Alder Reaction
作者:David MaGee、May Lee
DOI:10.1055/s-1997-5775
日期:1997.7
Two ketene equivalents (5 and 35) have been developed for use in the Diels-Alder reaction. These dienophiles exhibit a marked increase in reactivity in comparison with the more conventional acetoxyacrylonitrile. Conversions of the cycloadducts to the requisite ketones occurs under mild, and moderate to high yielding conditions.
Dihydropyridine-Based Multicomponent Reactions. Efficient Entry into New Tetrahydroquinoline Systems through Lewis Acid-Catalyzed Formal [4 + 2] Cycloadditions
作者:Rodolfo Lavilla、M. Carmen Bernabeu、Inés Carranco、José Luis Díaz
DOI:10.1021/ol027545d
日期:2003.3.1
tetrahydroquinolines in a stereoselective manner through a Lewis acid-catalyzed formal [4 + 2] cycloaddition. InCl(3) and Sc(OTf)(3) are the catalysts of choice for this process. The in situ generation of a reactive 1,4-dihydropyridine through the regioselective nucleophilic addition of cyanide to pyridiniumsalts allows a one-pot four-component transformation.
[EN] SMALL MOLECULE INDUCERS OF GDNF AS POTENTIAL NEW THERAPEUTICS FOR NEUROPSYCHIATRIC DISORDERS<br/>[FR] PETITES MOLÉCULES INDUCTRICES DE GDNF COMME NOUVELLE THÉRAPEUTIQUE POSSIBLE DES TROUBLES NEUROPSYCHIATRIQUES
申请人:UNIV COLUMBIA
公开号:WO2013028999A1
公开(公告)日:2013-02-28
The invention provides a compound having the structure (I), wherein A is a substituted or unsubstituted ring; Z is present or absent and when present is (II), wherein n is 0, 1, 2, 3, or 4; Y is -(CR11R12)-, -NH(CR11R12)- or -O(CR11R12)- wherein R11 and R12 are each hydrogen or combine to form a carbonyl; and wherein R1 to R10 are herein as described.
Enantioselective Formal Total Synthesis of (−)-Quinagolide
作者:Subhash P. Chavan、Appasaheb L. Kadam、Rajesh G. Gonnade
DOI:10.1021/acs.orglett.9b03477
日期:2019.11.15
The enantioselective formaltotalsynthesis of (−)-quinagolide has been accomplished in a linear sequence of 8 purification steps from pyridine. The key steps are (a) organocatalyzed Diels–Alder reaction for fixing all three stereocenters on piperidine ring; (b) protecting group enabled deoxygenation of isoquinuclidine skeleton under Birch reduction condition; (c) Lewis acid (TiCl4) catalyzed intramolecular