The Emergence of Quinone Methides in Asymmetric Organocatalysis
نویسندگان
چکیده
منابع مشابه
The Emergence of Quinone Methides in Asymmetric Organocatalysis.
Quinone methides (QMs) are highly reactive compounds that have been defined as "elusive" intermediates, or even as a "synthetic enigma" in organic chemistry. Indeed, there were just a handful of examples of their utilization in catalytic asymmetric settings until some years ago. This review collects organocatalytic asymmetric reactions that employ QMs as substrates and intermediates, from the e...
متن کاملThe Domestication of ortho-Quinone Methides
CONSPECTUS: An ortho-quinone methide (o-QM) is a highly reactive chemical motif harnessed by nature for a variety of purposes. Given its extraordinary reactivity and biological importance, it is surprising how few applications within organic synthesis exist. We speculate that their widespread use has been slowed by the complications that surround the preparation of their precursors, the harsh g...
متن کاملAsymmetric Conjugate Addition of ortho-Quinone Methides as a Pathway to the Core of Nomofungin
Asymmetric Conjugate Addition of ortho-Quinone Methides as a Pathway to the Core of Nomofungin Introduction: Tetracyclic structures are found at the core of many biologically active molecules. One class of compounds with a tetracyclic core is the family of communesin products. 1 These products have shown cytotoxicity against several leukemia cell lines as well as insecticidal activity against s...
متن کاملCatalytic Asymmetric Intramolecular [4+2] Cycloaddition of In Situ Generated ortho-Quinone Methides.
Herein, we describe the first catalytic asymmetric intramolecular [4+2] cycloaddition of in situ generated ortho-quinone methides. In the presence of a confined chiral imidodiphosphoric acid catalyst, various salicylaldehydes react with dienyl alcohols to give transient ortho-quinone methide intermediates, which undergo an intramolecular [4+2] cycloaddition to provide highly functionalized fura...
متن کاملAsymmetric cycloadditions of o-quinone methides employing chiral ammonium fluoride precatalysts.
The catalytic, enantioselective, [4 + 2] cycloaddition reaction of ortho-quinone methides with silyl ketene acetals is described. This mechanistically interesting reaction, initiated by a chiral cinchona alkaloid-derived ammonium fluoride "precatalyst" complex, affords a variety of alkyl- and aryl-substituted 3,4-dihydrocoumarin products in excellent yield and with good enantioselectivity.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Molecules
سال: 2015
ISSN: 1420-3049
DOI: 10.3390/molecules200711733