Aminocyclopentadienyl ruthenium complexes, which can be used as room-temperature racemization catalysts with lipases in the dynamic kinetic resolution (DKR) of secondary alcohols, were synthesized from cyclopenta-2,4-dienimines, Ru(3)(CO)(12), and CHCl(3): [2,3,4,5-Ph(4)(eta(5)-C(4)CNHR)]Ru(CO)(2)Cl (4: R = i-Pr; 5: R = n-Pr; 6: R = t-Bu), [2,5-Me(2)-3,4-Ph(2)(eta(5)-C(4)CNHR)]Ru(CO)(2)Cl (7: R = i-Pr; 8: R = Ph), and [2,3,4,5-Ph(4)(eta(5)-C(4)CNHAr)]Ru(CO)(2)Cl (9: Ar = p-NO(2)C(6)H(4); 10: Ar = p-ClC(6)H(4); 11: Ar = Ph; 12: Ar = p-OMeC(6)H(4); 13: Ar = p-NMe(2)C(6)H(4)). The tests in the racemization of (S)-4-phenyl-2-butanol showed that 7 is the most active catalyst, although the difference decreased in the DKR. Complex 4 was used in the DKR of various alcohols; at room temperature, not only simple alcohols but also functionalized ones such as allylic alcohols, alkynyl alcohols, diols, hydroxyl esters, and chlorohydrins were successfully transformed to chiral acetates. In mechanistic studies for the catalytic racemization, ruthenium hydride 14 appeared to be a key species. It was the major organometallic species in the racemization of (S)-1-phenylethanol with 4 and potassium tert-butoxide. In a separate experiment, (S)-1-phenylethanol was racemized catalytically by 14 in the presence of acetophenone.

Dynamic kinetic resolution (DKR) is an attractive method for the complete transformation of a racemic mixture into a single enantiomer. [1] The DKR of secondary alcohols is a prominent example, for which transition-metal-catalyzed racemization is coupled with enzymatic acylation. [2] In particular, B‰ckvall and co-workers have introduced a notable catalyst system that provides a wide range of chiral acetates in good yields and excellent optical purities. [2b±f] However, the catalyst for the racemization of secondary alcohols is activated at high temperature, and needs the corresponding ketones as hydrogen mediators. [3] Thus, the catalyst system requires a thermally stable lipase; p-chlorophenyl acetate has been selected as an acyl donor, [2c] because oxidation of the starting alcohols occurs when the conventional alkenyl acetates are used as acyl donors. [4] derivative has been determined. The decomposition of these complexes suggests rate-limiting loss of nitrous oxide leads to unusual and reactive late-transition-metal terminal oxo intermediates. Experimental Section3 a: [Ni(dppf)Cl 2 ], [27] (268 mg) dissolved in CH 2 Cl 2 (15 mL) was treated in one addition with 1 [22] (2 equivalents, 249 mg) suspended in methanol (60 mL). Rapidly a deep orange color developed and the solution volume was immediately reduced to ca 10 mL by evaporation at ambient temperatures. The resulting bright orange crystals were isolated by filtration and washed with portions of cold methanol (4 Â 10 mL) or until the filtrate was colorless. Recrystallization of this product from dichloromethane/ethanol at room temperature returns 243 mg (93 % yield) of 3 a. Elemental analysis calcd (%) C 34 H 28 FeN 2 NiO 2 P 2 ¥ 1 ³2CH 2 Cl 2 : C 59.26, H 4.05, N 3.88; found: C 59.43, H 4.28, N 3.64; IR (KBr,): n Ä 1480 m, 1449 s, 1436 s, 1307 m, 1194 w, 1182 w, 1168 m, 1096 s, 1036 m, 1028 m, 999 w, 983 m, 917 m, 827 w, 799 m, 744.3 s, 692 s, 638 w, 625 m, 556 m, 510, s, 494 s, 471 cm À1 m; 1 H NMR (400 MHz, CD 2 Cl 2 ): d 7.84 (m, 8 H), 7.52 (m, 4 H), 7.42 (t, J 7.3 Hz, 8 H), 4.42 (m, 4 H), 4.26 ppm (m, 4 H); 3 P NMR (162 MHz, CD 2 Cl 2 ): d 25.0 ppm (s) (UV/Vis: l max , (e max , m À1 cm À1 ) in CH 2 Cl 2 : 406 nm (655); differential scanning calorimetry (DSC): DH À 802 kcal mol À1 T onset 75 8C. Crystals suitable for X-ray diffraction were grown from CH 2 Cl 2 / Et 2 O at À 15 8C. Crystal data for 3 a: C 35 H 28 Cl 2 FeN 2 NiP 2 O 2 , M 755.99, 143 K, triclinic space group P1 ≈ , a 10.6210(8), b 11.3831(9), c 15.515(2) ä, a 84.021(2), b 72.745(2), g 69.790(1)8, V 1681.0(3) ä 3 , Z 2, 1 calcd 1.494 Mg m À3 , F(000) 772, 426 parameters; R 1 (wR 2 ) [I > 2s(I)] 0.064 (0.15), s(GOF) 0.98. Crystals of 3 a were mounted on glass fibers with epoxy resin and diffraction data was collected on a Bruker Smart CCD diffractometer equipped with a sealed molybdenum tube which was monochromated to give l 0.71073 ä. The structure was solved using direct methods and refined using full-matrix least-squares on F 2 with SHELXTL. With the exception of the disordered di...

Background:Motor deficits associated with Parkinson's disease (PD) have been well described, yet little attention has been paid to non-motor symptoms, especially cortical visual dysfunction. We investigated stereopsis, as well as the relationship between stereopsis and other cognitive function, in a sample of PD patients.Methods:We used Titmus stereotest plates for assessing stereopsis. Fifty-nine subjects (29 PD patients and 30 normal controls) were included in this study. The included patients underwent a neurological examination, clinical rating scale and neuropsychological tests.Results:Drug naïve PD patients showed decreased stereopsis on the Titmus fly stereopsis test (Pearson χ2=23.80, p<0.001) compared to PD patients with normal stereopsis. The Hoehn-Yahr stages and Unified Parkinson's Disease Rating Scale motor scores were significantly higher in patients with PD with abnormal stereopsis than in patients with PD with normal stereopsis (p=0.026; p=0.046). The frequency of abnormal visual perception/constructive function was greater in patients with PD with abnormal stereopsis compared to patients with PD with normal stereopsis (Pearson χ2=5.11, p=0.024).Conclusion:These findings suggest that stereopsis deficits and visual perception/constructive dysfunction are common in de novo PD patients.

The reaction of [2,3,4,5-Ph 4 (η 4 -C 4 CO)]Ru(CO) 3 (5a) with Na 2 CO 3 in aqueous acetone followed by low-temperature treatment with NH 4 Cl was reported to give the material A, which was formulated as the isopropyl alcohol complex [2,3,4,5-Ph 4 (η 4 -C 4 CO)](CO) 2 Ru-(HOCHMe 2 ) (3a). Reinvestigation of this reaction indicates that A is instead the isopropylamine complex [2,3,4,5-Ph 4 (η 4 -C 4 CO)](CO) 2 Ru(H 2 NCHMe 2 ) (4a). The formation of 4a is proposed to occur by formation of the imine of acetone followed by reduction of the imine by the (hydroxycyclopentadienyl)ruthenium hydride [2,3,4,5-Ph 4 (η 5 -C 4 COH)]Ru(CO) 2 H (2a) formed in the reaction of 5a with Na 2 CO 3 in aqueous acetone and subsequent acidification with aqueous NH 4 Cl.

Presently, lots of previous studies on biometrics employ convolutional neural networks (CNN) which requires a large amount of labeled training data. However, biometric data are considered as important personal information, and it is difficult to obtain large amounts of data due to individual privacy issues. Training with a small amount of data is a major cause of overfitting and low testing accuracy. To resolve this problem, previous studies have performed data augmentation that are based on geometric transforms and the adjustment of image brightness. Nevertheless, the data created by these methods have high correlation with the original data, and they cannot adequately reflect individual diversities. To resolve this problem, this study proposes iris image augmentation based on a conditional generative adversarial network (cGAN), as well as a method for improving recognition performance that uses this augmentation method. In our method, normalized iris images that are generated through arbitrary changes in the iris and pupil coordinates are used as input in the cGAN-based model to generate iris images. Due to the limitations of the cGAN model, data augmentation, which uses the periocular region, was found to fail with regard to the improvement of performance. Based on this information, only the iris region was used as input for the cGAN model. The augmentation method proposed in this paper was tested using NICE.II training dataset (selected from UBIRS.v2), MICHE database, and CASIA-Iris-Distance database. The results showed that the recognition performance was improved compared to existing studies.