Ruthenium-Catalyzed Enantioselective Carbon−Carbon Bond Forming Reaction via Allenylidene-Ene Process: Synthetic Approach to Chiral Heterocycles Such As Chromane, Thiochromane, and 1,2,3,4-Tetrahydroquinoline Derivatives

Abstract

Our previously disclosed ruthenium-catalyzed carbon-carbon bond forming reactions between propargylic alcohols and alkenes via an allenylidene-ene type pathway have been successfully applied to an enantioselective intramolecular cyclization for a variety of chiral heterocycles such as chromane, thiochromane, and 1,2,3,4-tetrahydroquinoline derivatives (up to 99% ee) by use of a suitable optically active diruthenium complex as a catalyst. The methodology described in this paper becomes a novel synthetic approach to chiral heterocycles, the structures of which are widely found in many natural and biologically active compounds.

Transition Metal Complexes of Neutral eta1-Carbon Ligands

“…21) [328,329]. As an extension of this work, related enantioselective intramolecular cyclizations were reported quite recently using suitable chiral diruthenium complexes [331]. The intramolecular version of these C-C bond-forming reactions to obtain a set of substituted chromanes 120, isolated as a mixture of two diastereoisomers, has also been described (Fig.…”

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

“…Ethanol was dried by sodium and freshly distilled prior to use. 2-Mercaptopyrimidine, 4-mercaptopyridine, ruthenium(III)chloride hydrate, 1,2-bis(diphenylphosphino)ethane, 1,1-bis(diphenylphosphino)methane and M(CO) 6 [M = Cr, Mo, W] were used as received from commercial sources. CpRu(PPh 3 ) 2 Cl was prepared as described in the literature [39].…”

“…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].…”

Catalytic, Enantioselective, Intramolecular Sulfenoamination of Alkenes with Anilines

“…For disconnection (3), Nishibayashi and co-workers developed a catalytic, enantioselective synthesis of 3,4-functionalized tetrahydroquinolines with excellent enantioselectivity. 7 In this process, a propargylic alcohol undergoes an intramolecular ene reaction with a pendant allyl amine under catalysis by a thiolate-bridged diruthenium complex. Finally, for disconnection (4), Lu and co-workers reported an enantioselective Friedel–Crafts alkylation using a prolinol silyl ether catalyst.…”