Organocatalytic Enantioselective Diels–Alder Reaction of 2‐Trifluoroacetamido‐1,3‐dienes with α,β‐Unsaturated Ketones

Abstract

We report herein the first examples of chiral phosphoric acid‐catalyzed enantioselective Diels–Alder reactions between 2‐trifluoroacetamido‐1,3‐dienes 1 and α,β‐unsaturated carbonyl compounds 2. Polysubstituted 1‐acetamido cyclohexenes 3 were formed in high yields with excellent diastereo‐ and enantioselectivities. The reaction proceeds through a stepwise process as shown by deuterium labelling experiments. A catalytic enantioselective three‐component reaction of 1, 2 and ortho‐hydroxybenzhydryl alcohols 4 was subsequently developed furnishing the densely functionalized hexahydroxanthenes 5 in a highly stereoselective manner. This multicomponent reaction generates four chemical bonds with concurrent creation of five contiguous stereocenters.

Enantioselective and Regiodivergent Synthesis of Dihydro-1,2-oxazines from Triene-Carbamates via Chiral Phosphoric Acid-Catalysis

“…In view of the aforementioned current state, coupled with our recent success in the development of various cycloaddition reactions with diene-carbamates, – we explored the feasibility of conducting challenging regioselective and enantioselective DA reactions using 1,3,5-triene-carbamates. Thus far, the linear N H-1,3,5-triene-1-carbamates (RNHCOOR′) have found limited use despite their potential to undergo diverse cycloadditions around of each unsaturation for the synthesis of advanced compounds .…”

Regio- and stereo-selective synthesis of β-phenylthio enamides via intramolecular 1,2-thiol migration

“…1 In the past decades, late-stage functionalization (LSF) has become a powerful and flexible tool for the construction of enamide derivatives (Scheme 1a). 2 Thus, developing facile and efficient synthetic methods for enamides has been an enduring topic in organic chemistry. Among the existing strategies, the direct C–N coupling reaction of amides with olefin is a particularly crucial pathway (Scheme 1b).…”