82(P-12) 後周期遷移金属アミン錯体を用いる触媒反応(ポスター発表の部)

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The catalytic reaction using late transition metal complex is mainly developing in the combination with phosphine ligand. In the meantime, there are a few examples of catalytic reactions using the combination of late transition metal and amine ligand. We report some catalytic reactions using late transition metal amine complex 1 and 2. (1) Catalytic asymmetric Michael reaction using a catalyst 1 A catalytic asymmetric Michael reaction is one of the most important carbon-carbon bond-forming reactions. We report a new protocol using a simple diamine-based Rh catalyst that gives chiral Michael products in up to 75%ee. Stirring of a mixture of tetrachlorobis(pentamethylcyclopentadienyl)dirhodium [Cp^*RhCl_2]_2 (6a), (R,R)-N-(4-t-butylbenzenesulfonyl)-1,2-diphenylethylenediamine [(R,R)-7b], and KOH (1:2:10 mol ratio) in CH_2Cl_2 at room temperature for 2h under argon gave a deep blue suspension, the supernatant of which could be used as a catalyst solution for the Michael addition of β-keto esters to unsaturated ketones. When a mixture of methyl 1-oxo-2-indanecarboxylate (3a), methyl vinyl ketone (4). and the in situ prepared Rh catalyst (1a:2:Rh=100:350:1 mol ratio) was stirred at -30℃ for 10h, (S)-methyl 1-oxo-2-(3'-oxobutyl)-2-indanecarboxylate [(S)-5a] was obtained in >99% yield with 75%ee. (2) Oxidative lactonization of diol using catalyst 2 The oxidative lactonization of diols is useful for the synthesis of a variety of natural products. A novel amino alcohol-based Ir bifunctional complex 2 acts as an efficient catalyst for oxidative lactonization of 1,4-or 1,5-diols with a substrate-to-catalyst molar ratio of 200-1000 in acetone or butanone. For example, a 50g scale reaction of 1,4-butanediol can be performed easily with high concentration with S/C=1000 to give γ-buyrolactone 9e in 89% yield after distillation. This method is high-yielding, clean, operationally simple and chemoselective. Moreover the reaction proceeds with broad functional group tolerance to give lactone in high yield at room temperature. The catalyst precursor Cp^*IrCl[OCH_2C(C_6H_5)_2NH_2] is isolated and characterized by a single-crystal X-ray analysis.
天然有機化合物討論会の論文
2002-09-01

82(P-12) 後周期遷移金属アミン錯体を用いる触媒反応(ポスター発表の部)

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