Synthesis of Diruthenium Complexes Containing Chiral Thiolate-Bridged Ligands and Their Application to Catalytic Propargylic Alkylation of Propargylic Alcohols with Acetone

Abstract

Novel diruthenium complexes containing chiral thiolate-bridged ligands are synthesized and characterized crystallographically. The chiral diruthenium complexes promote enantioselective propargylic alkylation of propargylic alcohols with acetone to give the corresponding propargylic alkylated products in good yields with moderate enantioselectivities (up to 35% ee).

Metal Vinylidenes and Allenylidenes in Catalysis: Applications in Anti‐Markovnikov Additions to Terminal Alkynes and Alkene Metathesis

“…Dicationic [Ru(MeCN)(pcymene)(bisoxazoline)](BF 4 ) 2 complexes were also used for the propargylation of furan and arene derivatives. [233] The most general results in the direct propargylation with propargylic alcohols were obtained in the presence of thiolate-bridged binuclear ruthenium precatalysts in the series [(Cp*)RuCl(m 2 -SR) 2 RuCl(Cp*)] by Nishibayashi et al [230] This ruthenium-catalyzed substitution of propargylic alcohols proceeded successfully with a variety of oxygen, nitrogen, phosphorus, sulfur, and carbon nucleophiles, including aliphatic alcohols, [230,237,238] phenols, [230,239] aromatic amines, [237,238] amides, [237,238] phosphine oxides, [237] thiols, [237,240] ketones, [238,[241][242][243][244][245] aromatic heterocycles, [238,246] and olefins [247] (Scheme 57). This catalyst also effects the dehydration of propargylic alcohols.…”

Ruthenium-Catalyzed Novel Carbon-Carbon Bond Forming Reactions via Ruthenium-Allenylidene Complexes

“…When an optically active 2a was treated with acetone at room temperature in the presence of 1a as catalyst, only a racemic alkylated product 3a was obtained [12] (eq 7). In this section, our investigation is described on the enantioselective [21] and diastereoselective [22] propargylic alkylations catalyzed by chiral thiolatebridged diruthenium complexes. This phenomenon prompted us to develop enantioselective propargylic substitution reaction of propargylic alcohols with acetone in the presence of a chiral thiolate-bridged diruthenium complex.…”

“…The catalytic propargylic alkylation was investigated in the presence of the thiolate-bridged diruthenium complexes as catalysts generated in situ from the reactions of [Cp*RuCl(µ 2 -Cl)] 2 with optically active thiols, the latter of which being prepared from the corresponding optically active alcohols [21]. Typical results of the reaction of 2 with acetone in the presence of a variety of catalysts are shown in Scheme 10.…”

Synthesis of cyclopentadienyl ruthenium 4-pyridine and 2-pyrimidine thiolates and their bimetallic group VI metal carbonyls

“…Over the last few decades, great attention has been paid to organoruthenium complexes containing thiolate ligands because of their interesting structures, reactivity and applications [1][2][3][4][5][6][7][8][9][10][11][12]. They have found applications in chemical transformations of organic molecules [6][7][8][9], in biological systems and as chemotherapeutic agents used in cancer treatment [10][11][12].…”

“…They have found applications in chemical transformations of organic molecules [6][7][8][9], in biological systems and as chemotherapeutic agents used in cancer treatment [10][11][12].…”