Efficient Activation of Acetals, Aldehydes, and Imines toward Silylated Nucleophiles by the Combined Use of Catalytic Amounts of [Rh(COD)Cl]2 and TMS-CN under Almost Neutral Conditions

Soga, Tsunehiko; Takenoshita, Haruhiro; Yamada, Masaaki; Mukaiyama, Teruaki

doi:10.1246/bcsj.63.3122

Cited by 39 publications

(5 citation statements)

References 19 publications

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“…1 H NMR (400 MHz, CDCl 3 ) δ 7.32 (t, 2H, J = 7.2 Hz), 7.24 (t, 1H, J = 7.2 Hz), 7.20 (d, 2H, J = 7.2 Hz), 3.98 (t, 1H, J = 6.4 Hz), 3.50 (s, 3H), 2.83 (t, 2H, J = 7.6 Hz), 2.24–2.09 (m, 2H); 13 C NMR (100 MHz, CDCl 3 ) δ 139.9, 128.9, 128.7, 126.7, 118.2, 69.7, 58.2, 35.1, 30.9. These data are consistent with reported literature values . HPLC (Lux cellulose-3), 90:10 hexane/ i -PrOH, 1 mL/min, t major = 7.6 min, t minor = 8.4 min, er = 74:26; [α] D 25 = +17.1 ( c 1.0, CHCl 3 ).…”

Section: Methodssupporting

confidence: 91%

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Stereocontrolled Cyanohydrin Ether Synthesis through Chiral Brønsted Acid-Mediated Vinyl Ether Hydrocyanation

Floreancig

2013

J. Org. Chem.

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Vinyl ethers can be protonated to generate oxocarbenium ions that react with Me3SiCN to form cyanohydrin alkyl ethers. Reactions that form racemic products proceed efficiently upon converting the vinyl ether to an α-chloro ether prior to cyanide addition in a pathway that proceeds through Brønsted acid-mediated chloride ionization. Enantiomerically enriched products can be accessed by directly protonating the vinyl ether with a chiral Brønsted acid to form a chiral ion pair. Me3SiCN acts as the nucleophile and PhOH serves as a stoichiometric proton source in a rare example of an asymmetric bimolecular nucleophilic addition reaction into an oxocarbenium ion. Computational studies provide a model for the interaction between the catalyst and the oxocarbenium ion.

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Section: Methodssupporting

confidence: 91%

“…These data are consistent with reported literature values. 50 HPLC (Lux cellulose-3), hexane/ i -PrOH 90:10, 1 mL/min, t major = 7.6 min, t minor = 8.4 min. er = 74:26.…”

Section: Methodsmentioning

confidence: 99%

Stereocontrolled Cyanohydrin Ether Synthesis through Chiral Brønsted Acid-Mediated Vinyl Ether Hydrocyanation

Floreancig

2013

J. Org. Chem.

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“…The palladium‐catalyzed hydrolysis of acetals and ketals, which lead to the corresponding carbonyl compounds, was reported by Lipshutz et al,19 and the rhodium‐catalyzed substitution reaction of acetals with TMSCN (TMS=trimethylsilyl) to produce α‐alkoxycyanides was reported by Mukaiyama and co‐workers 20. To our knowledge, however, catalytic addition of an acetal carbon–oxygen bond to carbon–carbon multiple bonds is not known.…”

Section: Palladium‐catalyzed Carboalkoxylation Of the O‐alkynylbenzalmentioning

confidence: 88%

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et al. 2002

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Synthetic procedures of ligands L2 and TEPA, as well as the copper(ii) complex of L2 have been reported elsewhere. [18, 20] L1: 2,2-Diphenylethylamine (1.97 g, 10 mmol) and 2-vinylpyridine (5.25 g, 50 mmol) were heated to reflux in CH 3 OH (20 mL) containing acetic acid (3.01 g, 50 mmol) for 10 days. The solvent was removed by evaporation, and the resulting viscous material was dissolved in H 2 O (200 mL) and extracted with CHCl 3 (3 î 200 mL). After drying over anhydrous K 2 CO 3 , evaporation of the organic solvent gave yellow oily material, from which L1 was isolated by SiO 2 column chromatography (CHCl 3 /AcOEt as eluent) in 54 % yield (2.21 g); 1 H NMR (300 MHz, CDCl 3 ): d ¼ 2.76±2.96 (m, 8 H; -CH 2 -CH 2 -Py), 3.16 (d, J ¼ 7.5 Hz, 2 H; -CH 2 -CH-Ph 2 ), 4.09 (t, J ¼ 7.5 Hz, 1 H; -CH-Ph 2 ), 6.76 (d, J ¼ 7.8 Hz, 2 H; H py-5 ), 7.03±7.26 (m, 12 H; C 6 H 4 and H py-3 ), 7.43 (td, J ¼ 1.8 and 7.8 Hz, 2 H; H py-4 ), 8.50 ppm (ddd, J ¼ 0.9, 1.8, and 4.8 Hz, 2 H; H py-6 ); FAB-HRMS (positive ion): calcd for C 28 H 29 N 3 : m/z 406.2283; found: m/z 406.2289 [M þ ]. [Cu II (L1)(ClO 4 ) 2 ]¥H 2 O: Ligand L1 (122.3 mg, 0.3 mmol) was treated with Cu II (ClO 4 ) 2 ¥6 H 2 O (111.2 mg, 0.3 mmol) in CH 3 OH (10 mL) for 30 min at room temperature. Addition of Et 2 O (200 mL) to the mixture gave blue solids that were isolated by decantation, washed three times with Et 2 O, and dried (83 % yield). Single crystals were obtained by vapor diffusion of Et 2 O into a solution of the complex in CH 3 OH. FTIR (KBr): ñ ¼ 1130, 1043, 621 cm À1 (ClO 4 À ); FAB-MS (positive ion): m/z 569.2 [M þ ]; elemental analysis for [Cu II (L1)(ClO 4 ) 2 ]¥H 2 O, calcd (%) for C 28 H 31 O 9 N 3 CuCl 2 : C 48.88, H 4.54, N 6.11; found: C 48.72, H 4.48, N 6.06. [Cu II (TEPA)(ClO 4 )]ClO 4 : The TEPA ligand (332.5 mg, 1.0 mmol) was treated with Cu II (ClO 4 ) 2 ¥6 H 2 O (370.5 mg, 1.0 mmol) in CH 3 CN (10 mL) for 30 min at room temperature. Addition of Et 2 O (200 mL) to the mixture gave a blue oily material that was isolated by decantation and redissolved into CH 3 OH (10 mL). Addition of the CH 3 OH solution into Et 2 O (200 mL) gave blue solids that were isolated by decantation, washed with Et 2 O three times, and dried (95 % yield). Single crystals were obtained by vapor diffusion of Et 2 O into a solution of the complex in CH 3 OH. FTIR (KBr): ñ ¼ 1143, 1081, 625 cm À1 (ClO 4 À ); FAB-MS (positive ion): m/z 494.07 [M þ ]; elemental analysis for [Cu II (TEPA)(ClO 4 )](ClO 4 ), calcd (%) for C 21 H 28 O 8 N 4 CuCl 2 : C 39.98, H 4.47, N 8.88; found: C 40.18, H 4.16, N 8.87.Caution! The perchlorate salts in this study are all potentially explosive and should be handled with care.Kinetic measurements for the reaction of copper(ii) complexes (0.2 mM) and H 2 O 2 were performed by using a multi-scan double mixing stoppedflow spectrophotometer designed for low-temperature measurements (RSP-1000, Unisoku Co., Ltd.) in CH 3 OH at À90 8C. The reaction of [Cu II (L1)(ClO 4 ) 2 ] and H 2 O 2 at the higher concentration ( Figure S10 in the Supporting Infor...

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“…In this context, a-alkoxynitriles, a protected form of cyanohydrin, are synthetically valuable compounds that can serve as a synthon for many industrially important compounds, e.g., 3-amino-2-alkenenitriles, a-alkoxyketones, etc. 19 The synthesis of a-alkoxynitriles, through cyanation of acetals with trimethylsilyl cyanide (TMSCN) in the presence of different Lewis acids, such as BiBr 3 , 20 [Rh(COD)Cl] 2 , 21 SnCl 2 , 22 TiCl 4 , 23 ZnI 2 , 24 BF 3 Á Et 2 O 25 and MgI 2 etherate, 26 has been reported. Other cyanating agents, such as cyanoamine in the presence of trichlorosilyl triflate, have also been used to catalyze cyanation of acetals and orthoesters.…”

Section: Introductionmentioning

confidence: 99%

Design and construction of polyaromatic group containing Cd(ii)-based coordination polymers for solvent-free Strecker-type cyanation of acetals

et al. 2022

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Efficient Activation of Acetals, Aldehydes, and Imines toward Silylated Nucleophiles by the Combined Use of Catalytic Amounts of [Rh(COD)Cl]2 and TMS-CN under Almost Neutral Conditions

Cited by 39 publications

References 19 publications

Stereocontrolled Cyanohydrin Ether Synthesis through Chiral Brønsted Acid-Mediated Vinyl Ether Hydrocyanation

Stereocontrolled Cyanohydrin Ether Synthesis through Chiral Brønsted Acid-Mediated Vinyl Ether Hydrocyanation

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Design and construction of polyaromatic group containing Cd(ii)-based coordination polymers for solvent-free Strecker-type cyanation of acetals

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