Dearomative Alkylation-Based Two-Step cis-Diastereoselective Synthesis of Indoline-2,3-Fused Chromans and Tetrahydropyrans.
J Org Chem
; 2024 Oct 03.
Article
in En
| MEDLINE
| ID: mdl-39360679
ABSTRACT
Herein, we describe a two-step, cis-diastereoselective synthesis of indoline-2,3-fused chromans from 3-substituted indoles. The method proceeds without intermediacy of ortho-quinone methides and leverages the dual function of TBS-protected 2-hydroxybenzyl iodides both as highly reactive alkylating agents in a t-BuONa/Et3B-promoted dearomative alkylation step and as a source of masked phenoxide nucleophiles in a subsequent TBAF-induced one-pot deprotection-cyclization step of the resulting indolenines. Importantly, this two-step protocol can also be extended to access indoline-2,3-fused tetrahydropyrans. These syntheses of indoline-2,3-fused chromans and tetrahydropyrans proceed with operational convenience, use easily accessible substrates and reagents, and feature broad substrate scope, high yields and complete diastereoselectivity. Furthermore, the synthesized products have the potential to undergo late-stage functionalization.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
J Org Chem
/
J. org. chem
/
Journal of organic chemistry
Year:
2024
Document type:
Article
Affiliation country:
India
Country of publication:
United States