Contrasting Carboannulation Involving δ-Acetoxy Allenoate as a Four-Carbon Synthon Using DABCO and DMAP: Access to Spiro-carbocyclic and m-Teraryl Scaffolds

Spiro-annulation involving delta-acetoxy allenoate and alkyl benzoisothiazole dioxide (N-sulfonyl ketimine) triggered by DABCO/MeCO2H combination leads to an essentially single diastereomer via chemo- and regiospecific [4 + 2]-carboannulation and a new hydroxyl group is introduced. In contrast, DMAP...

Full description

Saved in:
Bibliographic Details
Published in:Organic letters Vol. 23; no. 3; pp. 1123 - 1129
Main Authors: Kumar, A. Sanjeeva, Chauhan, Sachin, Swamy, K. C. Kumara
Format: Journal Article
Language:English
Published: WASHINGTON Amer Chemical Soc 05.02.2021
Subjects:
Chemistry
Chemistry, Organic
Physical Sciences
Science & Technology
ISSN:1523-7060, 1523-7052, 1523-7052
Online Access:Get more information
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Spiro-annulation involving delta-acetoxy allenoate and alkyl benzoisothiazole dioxide (N-sulfonyl ketimine) triggered by DABCO/MeCO2H combination leads to an essentially single diastereomer via chemo- and regiospecific [4 + 2]-carboannulation and a new hydroxyl group is introduced. In contrast, DMAP-catalyzed benzannulation using the same reactants affords unsymmetrical m-teraryls via Mannich coupling, sequential proton transfers, and C-N bond cleavage. Here, delta-acetoxy allenoate serves as a 4C-synthon and the carboannulation is completely base dependent and mutually exclusive.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:1523-7060
1523-7052
1523-7052
DOI:10.1021/acs.orglett.1c00076