30189-87-8Relevant articles and documents
Mild and selective activation and substitution of strong aliphatic C-F bonds
Janjetovic, Mario,Tr?ff, Annika M.,Hilmersson, G?ran
, p. 3772 - 3777 (2015)
A procedure for chemoselectively manipulating the strong aliphatic C-F bond with direct transformation into a C-N bond under mild conditions is reported. The activation and subsequent substitution of primary alkyl fluorides is mediated by La[N(SiMe3)2]3, and results in high to excellent yields of tertiary amines. The methodology displays high selectivity towards the C(sp3)-F bond, and a variety of secondary amines are applicable as nucleophiles. Mechanistic investigations reveal a reaction that is first order with respect to [La[N(SiMe3)2]3], [R1R2NH], and [alkyl fluoride], and a 6-membered cyclic transition state is proposed. In addition, 1H NMR spectroscopy shows that La[N(SiMe3)2]3 is the active species involved in the substitution and that protonolysis of the amine, yielding La[NR1R2]3, lowers the reactivity.
Synthesis of 1,3-Amino Alcohols, 1,3-Diols, Amines, and Carboxylic Acids from Terminal Alkynes
Zeng, Mingshuo,Herzon, Seth B.
, p. 8604 - 8618 (2015/09/15)
The half-sandwich ruthenium complexes 1-3 activate terminal alkynes toward anti-Markovnikov hydration and reductive hydration under mild conditions. These reactions are believed to proceed via addition of water to metal vinylidene intermediates (4). The functionalization of propargylic alcohols by metal vinylidene pathways is challenging owing to decomposition of the starting material and catalytic intermediates. Here we show that catalyst 2 can be employed to convert propargylic alcohols to 1,3-diols in high yield and with retention of stereochemistry at the propargylic position. The method is also amenable to propargylic amine derivatives, thereby establishing a route to enantioenriched 1,3-amino alcohol products. We also report the development of formal anti-Markovnikov reductive amination and oxidative hydration reactions to access linear amines and carboxylic acids, respectively, from terminal alkynes. This chemistry expands the scope of products that can be prepared from terminal alkynes by practical and high-yielding metal-catalyzed methods.
