Asymmetric Oxidative Cation/Olefin Cyclization of Polyenes: Evidence for Reversible Cascade Cyclization
نویسندگان
چکیده
منابع مشابه
Asymmetric oxidative cation/olefin cyclization of polyenes: evidence for reversible cascade cyclization.
The biosynthesis of cyclic terpenes from polyene precursors by cyclase enzymes is one of nature’s most elegant chemical transformations.[1] The ease with which nature creates complex molecular architectures from achiral precursors has motivated efforts to develop similarly powerful synthetic methodologies.[2] Alimited number of asymmetric methods have been developed,[3] including the notable Br...
متن کاملEnantioselective Cascade Cyclization/Protodemetalation of Polyenes with N3Pt2+ Catalysts
The combination of the N-based pincer ligand PyBOX with Pt2+ leads to new catalysts for the enantioselective cycloisomerization of dienyl- and trienyl-ols. The mechanistic combination of electrophilic cyclization followed by rapid protodemetalation is surprising and leads to a powerful construct for developing new reactions.
متن کاملCatalytic diastereo- and positionselective oxidative mono-cyclization of 1,5,9-trienes and polyenes.
Ruthenium tetroxide (1 mol%) has been used as a catalyst for the oxidative mono-cyclization of 1,5,9-trienes and polyenes. The poly-unsaturated substrates underwent mono-cyclization with a high degree of diastereo- and positionselectivity to produce mono-tetrahydrofuran diols with a varying degree of unsaturation. Up to four new stereogenic centers were created in this single step transformatio...
متن کاملLewis acid-mediated radical cyclization: stereocontrol in cascade radical addition-cyclization-trapping reactions.
An efficient approach for achieving radical cyclizations by using hydroxamate ester as a coordination tether with Lewis acid was studied. The chiral Lewis acid-mediated cascade radical addition-cyclization-trapping reaction proceeded smoothly with good enantio- and diastereoselectivities, providing various chiral γ-lactams.
متن کاملAsymmetric syntheses of 8-oxabicyclo[3,2,1]octanes: a cationic cascade cyclization.
tropane alkaloids, and consequently there is an increasing interest in their potential pharmaceutical use, particularly against cocaine abuse. Compelled by the interesting biological activities of 8oxatropanes, many groups have embarked on the search for new methodologies to construct this bicyclic structure. For example, Molander and co-workers have reported a Lewis acid promoted double allyla...
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: Angewandte Chemie International Edition
سال: 2008
ISSN: 1433-7851,1521-3773
DOI: 10.1002/anie.200801423