Organic Reactions in Water: An Efficient Zinc-Mediated Stereoselective Synthesis of (<i>E</i>)- and (<i>Z</i>)-Trisubstituted Alkenes Using Unactivated Alkyl Halides
[reaction: see text] Treatment of the acetyl derivatives of the Baylis-Hillman adducts 3-hydroxy-2-methylene-alkanoates and 3-hydroxy-2-methylene-alkanenitriles with unactivated alkyl halides in the presence of Zn in saturated aqueous NH(4)Cl solution at room temperature afforded (2E)-2-substituted-alk-2-enoates in the first case and (2Z)-2-substituted-alk-2-enenitriles with high (Z)-selectivity in
Chemo-, regio- and stereoselective addition of triorganoindium reagents to acetates of Baylis–Hillman adducts: a new strategy for the synthesis of (E)- and (Z)-trisubstituted alkenes
作者:Brindaban C. Ranu、Kalicharan Chattopadhyay、Ranjan Jana
DOI:10.1016/j.tetlet.2007.03.154
日期:2007.5
The addition of several trialkyl or triarylindium reagents to the acetates of Baylis–Hillmanadducts proceeds readily under the catalysis of copper and palladium derivatives. The reactions of trialkylindiums are catalyzed efficiently by CuI whereas additions of triarylindiums produce better results with Pd(PPh3)4. The reactions with 3-acetoxy-2-methylenealkanoates provide (E)-alkenes, whereas similar
Applications of the Baylis–Hillman reaction 2: a simple stereoselective synthesis of (E)- and (Z)-trisubstituted alkenes
作者:Deevi Basavaiah、Pakala K. S. Sarma、Anagani K. D. Bhavani
DOI:10.1039/c39940001091
日期:——
Reaction of Grignard reagents with methyl 3-acetoxy-2-methylenealkanoates produces (2E)-2-substituted alk-2-enoates, whereas a similar reaction with 3-acetoxy-2-methylenealkanenitriles provides (2Z)-2-substituted alk-2-enenitriles in high (Z)-stereoselectivity.
Organic Compounds Suitable For Modulating Fragrance Compositions
申请人:Granier Thierry
公开号:US20110200549A1
公开(公告)日:2011-08-18
Disclosed are compounds having the ability to modulate, namely to improve, enhance and/or modify fragrance compositions due to their ability to inhibit cytochrome P450 enzymes, e.g. CYP2A, e.g. 2A13 and 2A6, and CYP2B6.
Mixtures of chiral monophosphorus compounds used as ligand systems for asymmetric transition metal catalysis
申请人:Reetz T. Manfred
公开号:US20060014981A1
公开(公告)日:2006-01-19
The invention relates to certain chiral transition metal catalysts, to the metal of which at least two structurally different monophosphorus ligands are bonded, at least one of said monophosphorus ligands being chiral. Said chiral transition metal catalysts are suitable as catalysts for use in asymmetric transition metal-catalyzed reactions, providing better enantioselectivities than in cases where only one structurally defined ligand is used.