Diastereoselective Base-Catalyzed Formal [4 + 2] Cycloadditions of N-Sulfonyl Imines and Cyclic Anhydrides
نویسندگان
چکیده
منابع مشابه
Stereoselective Lewis base catalyzed formal 1,3-dipolar cycloaddition of azomethine imines with mixed anhydrides.
Stereoselective synthesis of pyrazolidinones via dipolar cycloaddition of azomethine imines with active esters under Lewis base catalysis is presented. The active esters are readily generated in situ from the corresponding acids. Products, which are obtained with excellent diastereocontrol and high enantioselectivity, contain along with the pyrazolidinone core also the tetrahydroisoquinoline st...
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A strategy for exo and enantioselective 1,3-dipolar cycloaddition of azomethine imines to 2-acryloyl-3-pyrazolidinone is described. The corresponding cycloadducts are isolated with high diastereoselectivities (up to >96:4 exo/endo) and enantioselectivities (up to 98% ee).
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An efficient diastereoselective rhodium catalyzed synthesis of indolines possessing two contiguous tetrasubstituted carbon centers has been achieved with good to excellent yields using ortho-vinylanilines and iminocarbenes derived from N-sulfonyl-1,2,3-triazoles. The reaction affords excellent cisdiastereoselectivity through the initial formation of a N-ylide followed by intramolecular trapping...
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The reaction of N-sulfonyl propargylamides in the presence of a base catalyst selectively affords 5-sulfonylmethyl oxazoles via 1,4-sulfonyl migration. Allenes have been established as the key intermediates. Experimental evidence has been provided to support a two-step mechanism in the cyclization.
متن کاملDiastereoselective Synthesis of γ- and δ-Lactams from Imines and Sulfone-Substituted Anhydrides
Sulfone-substituted γ- and δ-lactams have been prepared in a single step with high diastereoselectivity. Sulfonylglutaric anhydrides produce intermediates that readily decarboxylate to provide δ-lactams with high diastereoselectivity. Substituents at the 3- or 4-position of the glutaric anhydride induce high levels of stereocontrol. Sulfonylsuccinic anhydrides produce intermediate carboxylic ac...
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ژورنال
عنوان ژورنال: Organic Letters
سال: 2017
ISSN: 1523-7060,1523-7052
DOI: 10.1021/acs.orglett.7b00468