Synthesis of α-Amino Ketones from Terminal Alkynes via Rhodium-Catalyzed Denitrogenative Hydration of N-Sulfonyl-1,2,3-triazoles
摘要:
N-Sulfonyl-1,2,3-triazoles react with water in the presence of a rhodium catalyst to produce alpha-amino ketones in high yield. An intermediary alpha-imino rhodium(II) carbenoid undergoes insertion into the O-H bond of water. This transformation formally achieves 1,2-aminohydroxylation of terminal alkynes in a regioselective fashion when combined with the copper(I)-catalyzed 1,3-dipolar cycloaddition with N-sulfonyl azides.
The rhodium(II)‐catalyzed denitrogenative coupling of N‐alkylsulfonyl 1,2,3‐triazoles with 1,3,5‐trioxane led to nine‐membered‐ringed trioxazonines in moderate‐to‐good yields. 1,3,5‐Trioxane, acting as an oxygen nucleophile, reacted with the α‐aza‐vinylcarbene intermediate, giving rise to ylide formation, which was probably the key step in the reaction. Triazoles that contained aryl substituents with
An efficient room-temperature method for the synthesis of 1-sulfonyl-1,2,3-triazoles from in situgeneratedcopper(I) acetylides and sulfonyl azides is described. The copper(I) thiophene-2-carboxylate (CuTC) catalyst produces the title compounds under both nonbasic anhydrous and aqueous conditions in good yields.
A new procedure for the stereoselective synthesis of syn alpha-amino beta-oxy ketones is reported. It consists of two steps; in the first step, alpha-amino silyl enol ethers having a (Z) geometry are prepared from 1-alkynes via 1-sulfonyl-1,2,3-triazoles. In the second step, the silyl enol ethers undergo the TiCl4-mediated Mukaiyama aldolreaction with aldehydes to produce alpha-amino beta-oxy ketones
Synthesis of 2-Substituted 2-Amino Ketones by Rhodium-Catalyzed Reaction of<i>N</i>-Sulfonyl-1,2,3-triazoles with 2-Alkenols
作者:Tomoya Miura、Takamasa Tanaka、Qiang Zhao、Scott G. Stewart、Masahiro Murakami
DOI:10.1002/hlca.201600320
日期:2017.2
A study on a rhodium(II)‐catalyzed reaction of N‐sulfonyl‐1,2,3‐triazoles with 2‐alkenols is reported. The reaction is initiated by insertion of an α‐imino carbene into the O–H linkage of alcohol, forming a 2‐alkenoxy enamide intermediate. A thermal [3,3]‐sigmatropicrearrangement follows to yield 2‐substituted 2‐amino ketone in a stereoselective manner. The successful application of this methodology