H-Bond-Directing Organocatalyst for Enantioselective [4 + 2] Cycloadditions via Dienamine Catalysis
نویسندگان
چکیده
منابع مشابه
Asymmetric organocatalytic formal [2 + 2]-cycloadditions via bifunctional H-bond directing dienamine catalysis.
A new concept in organocatalysis allowing for the construction of cyclobutanes with four contiguous stereocenters with complete diastereo- and enantiomeric control by a formal [2 + 2]-cycloaddition is presented. The concept is based on simultaneous dual activation of α,β-unsaturated aldehydes and nitroolefins by amino- and hydrogen-bonding catalysis, respectively. A new bifunctional squaramide-...
متن کاملDual catalysis in enantioselective oxidopyrylium-based [5 + 2] cycloadditions.
A new method for effecting catalytic enantioselective intramolecular [5 + 2] cycloadditions based on oxidopyrylium intermediates is reported. The dual catalyst system consists of a chiral primary aminothiourea and a second achiral thiourea. Experimental evidence points to a new type of cooperative catalysis with each species being necessary to generate a reactive pyrylium ion pair that undergoe...
متن کاملEnantioselective polyene cyclization via organo-SOMO catalysis.
The first organocatalytic enantioselective radical polycyclization has been accomplished using singly occupied molecular orbital (SOMO) catalysis. The presented strategy relies on a selective single-electron oxidation of chiral enamines formed by condensation of polyenals with an imidazolidinone catalyst employing a suitable copper(II) oxidant. The reaction proceeds under mildly acidic conditio...
متن کاملA combination of directing groups and chiral anion phase-transfer catalysis for enantioselective fluorination of alkenes.
We report a catalytic enantioselective electrophilic fluorination of alkenes to form tertiary and quaternary C(sp3)-F bonds and generate β-amino- and β-aryl-allylic fluorides. The reaction takes advantage of the ability of chiral phosphate anions to serve as solid-liquid phase transfer catalysts and hydrogen bond with directing groups on the substrate. A variety of heterocyclic, carbocyclic, an...
متن کاملGlycoside bond formation via acid-base catalysis.
Acid-base catalyzed glycosyl donor and then glycosyl acceptor activation with phenylboron difluoride or diphenylboron fluoride permits hydrogen bond mediated intramolecular S(N)2-type glycosidation in generally high anomeric selectivity.
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: Organic Letters
سال: 2016
ISSN: 1523-7060,1523-7052
DOI: 10.1021/acs.orglett.5b03575