Synthesis of Unsymmetrically Substituted 1,3-Butadiynes and 1,3,5-Hexatriynes via Alkylidene Carbenoid Rearrangements
作者:Annabelle L. K. Shi Shun、Erin T. Chernick、Sara Eisler、Rik R. Tykwinski
DOI:10.1021/jo026481h
日期:2003.2.1
Unsymmetrically substituted 1,3-butadiynes and 1,3,5-hexatriynes are synthesized in four steps from commercially available aldehydes or carboxylic acids. The key step in this process involves a Fritsch-Buttenberg-Wiechell rearrangement, in which an alkylidene carbenoid intermediate subsequently rearranges to the desired polyyne. This rearrangement proceeds under mild conditions, and it is tolerant
Three different substituted thiazoles have been successfully synthesized from readily available propargylic alcohols. Various secondary propargylic alcohols or tertiary propargylic alcohols participated well in the reaction, providing the desired products in good yields. This method provides a flexible and rapid route to substituted thiazoles.
Gold-Catalyzed Hydroamination of Propargylic Alcohols: Controlling Divergent Catalytic Reaction Pathways To Access 1,3-Amino Alcohols, 3-Hydroxyketones, or 3-Aminoketones
作者:Victor Laserna、Michael J. Porter、Tom D. Sheppard
DOI:10.1021/acs.joc.9b00988
日期:2019.9.20
Alternatively, by using a catalytic quantity of aniline, 3-hydroxyketones can be obtained in high yield directly from propargylic alcohols. Further manipulation of the reaction conditions enables the selective formation of 3-aminoketones via a rearrangement/hydroamination pathway. The utility of the new chemistry was exemplified by the one-pot synthesis of a selection of N-arylpyrrolidines and N-arylpiperidines
Gold-Catalyzed 1,4-Carbooxygenation of 3-En-1-ynamides with Allylic and Propargylic Alcohols<i>via</i>Non-Claisen Pathways
作者:Sovan Sundar Giri、Li-Hsuan Lin、Prakash Daulat Jadhav、Rai-Shung Liu
DOI:10.1002/adsc.201601092
日期:2017.2.20
Gold‐catalyzed1,4‐carbooxygenations of 3‐en‐1‐ynamides with allylic alcohols and propargylic alcohols yield α,β‐unsaturated amides through non‐Claisen pathways; the mechanisms involve ionization of the initial gold enol ethers to form C‐bound gold dienolates that capture allylic or propargylic cations to yield the observed products. Our 18O‐labeling experiments exclude a direct gold‐catalyzed allylation
We found that the combination of [Ir(cod)Cl]2 and rac-BINAP served as an efficient catalyst for the [2+2+2] cycloaddition of 2,7-nonadiyne derivatives and related compounds with alkynyl ketones and alkynyl esters. The corresponding products were obtained in high yields under mild reaction conditions.