Prostereogenic Face and Orientation Selective Oxidative Coupling Reaction between Methyl Methacrylate and 2,5-Dihydrofuran Catalyzed by a Ruthenium(0) Compound

Abstract

We disclose the first prostereogenic face and orientational control of coordinated olefins in an oxidative coupling reaction at a transition-metal center. Chemo-, regio-, and diastereoselective cross-dimerization between methyl methacrylate (MMA) and 2,5-dihydrofuran is catalyzed by Ru(η 6 -naphthalene)(η 4 -1,5-COD) (1; 5 mol %) at 0 °C in 24 h without use of solvent to give methyl rac-(2S)-3-[(3R)-2,3dihydrofuran-3-yl]-2-methylpropionate (2a) in 81% yield.

Synthesis of conjugated diene complexes of ruthenium(0) derived from Ru(η6-naphthalene)(η4-1,5-COD): Z to E isomerisation of coordinated 1,3-pentadiene

“…This hypothesis is supported by the observed distances of 1.478(4) and 1.491(4) Å, respectively, for C(1)e C(5) and C(4)eC (11). However, since the 1 H NMR spectrum of 8a at room temperature showed only one A 2 B 2 X pattern for the ortho-, meta-and para-phenyl protons, the phenyl groups must be rotating in solution.…”

“…The lability of the coordinated naphthalene in [Ru(h 6 -C 10 H 8 )(h 4 -1,5-COD)] (1) [1e3] is responsible for the ability of this complex, especially in the presence of acetonitrile, to catalyse some important organic reactions, including alkene hydrogenation [3] and isomerisation [4,5], the selective tail-to-tail dimerisation of unsaturated compounds such as methyl acrylate [6,7], methyl methacrylate [8] and acrylonitrile [9], and cross dimerisations between butadiene and methyl methacrylate [10], and between 2,5-dihydrofuran and methyl methacrylate [11]. An excess of butadiene in the absence of acetonitrile completely displaces naphthalene from complex 1 to give supine, prone-[Ru(h 3 :h 3 -2,6-octadiene-1,8-diyl)(h 4 -1,5-COD)] as a result of oxidative coupling of the butadiene units in an intermediate [Ru(h 4 -cisoid-butadiene)(h 2 -transoid-butadiene)(h 4 -1,5-COD)] that can be detected at low temperature [12].…”

Oxidative coupling reactions at ruthenium(0) and their applications to catalytic homo- and cross-dimerizations¶

“…series of new ruthenium(0) complexes containing a coupled dienylcarboxylate ligand was obtained (Scheme 9)[77,78]. These processes involve a CC bond-forming step between 1,3butadiene and conjugated carbonyl compound, and subsequent migration steps of the hydrogen atoms.…”

Ru(0)-catalyzed C3-selective Coupling Reactions of Unsaturated 5-Membered Heterocycles with Methyl Methacrylate and Methacryl Amide

“…Although this C3-selective coupling of 2a showed a broad scope for conjugated dienes, the substrate scope for conjugated carbonyl compounds was limited. 4 In fact, while reaction of 2a with methyl methacrylate (3a) produced 4aa in high yield, even closely related methacryl amide (3b) remained unreacted (Scheme 1). As part of our ongoing program to prepare new (naphthalene)ruthenium(0) complexes having a cyclic diene ligand, 5 we prepared [Ru(η 6 -naphthalene)(rac-η 4 -bicyclo[3.3.1]-nona-2,6-diene)] (1b).…”

“…Consistently, the C(8)=C(9) and C(12)=C(13) bond distances in 7b (1.3891.392 ¡) are slightly shorter than those in 1b (1.411 1.414 ¡). 4 This probably arises from weaker π-back donation to the bnd ligand in 7b than 1b, because of the strong electronwithdrawing nature of the carbonyl group. The¯CO bands for 7a (1964 cm ¹1 ) and 7b (1960 cm…”