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Gold‐Catalyzed [4+2]‐ and [3+3]‐Annulations of Ynamides with 1‐Yn‐3‐ols to Access Six‐Membered Carbocycles and Oxacycles via Three Distinct Cyclizations
Author(s) -
Giri Sovan Sundar,
Liu RaiShung
Publication year - 2017
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201700784
Subject(s) - chemistry , catalysis , yield (engineering) , amide , enol , claisen rearrangement , cycloisomerization , stereochemistry , combinatorial chemistry , medicinal chemistry , organic chemistry , materials science , metallurgy
Three distinct strategies for catalytic annulations between ynamides and 1‐yn‐3‐ols are described; the resulting carbo‐ and heterocycles were produced efficiently in one‐pot operations using a gold catalyst. The chemoselectivities of these annulations are controlled by variations of the substituents of the ynamides and the 1‐yn‐3‐ols. This reaction sequence involves initial alkoxylations of ynamides, followed by Claisen rearrangement of propargylic enol ethers, and ends with 6‐ endo ‐ trig cyclizations of 1‐allenyl‐5‐amide intermediates. Among these cascade annulations, the cyclizations of 5‐allenyl‐1‐amides to yield 5,6‐dihydro‐2‐pyranones and 6‐alkylenecyclohex‐2‐ene‐1‐carboxamides are unprecedented in the literature.