Asymmetric Cooperative Catalysis of Strong Bronsted Acid-Promoted Reactions Using Chiral Ureas
نویسندگان
چکیده
منابع مشابه
Asymmetric cooperative catalysis of strong Brønsted acid-promoted reactions using chiral ureas.
Cationic organic intermediates participate in a wide variety of useful synthetic transformations, but their high reactivity can render selectivity in competing pathways difficult to control. Here, we describe a strategy for inducing enantioselectivity in reactions of protio-iminium ions, wherein a chiral catalyst interacts with the highly reactive intermediate through a network of noncovalent i...
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A binary catalyst system for the enantioselective bromocycloetherification of 5-arylpentenols is described. The combination of an achiral Lewis base and a chiral Brønsted acid affords good enantioselectivities for the cyclization of Z configured 5-arylpentenols to form bromomethyltetrahydrofurans. The constitutional site selectivity is highly dependent upon the aromatic substituent and the conf...
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ژورنال
عنوان ژورنال: Science
سال: 2010
ISSN: 0036-8075,1095-9203
DOI: 10.1126/science.1182826