COAP-Pd Catalyzed Asymmetric Allylic Alkylation of Azlactones with MBH Carbonates: Access to Unnatural α-Quaternary Stereogenic Glutamic Acid Derivatives.

A palladium-catalyzed regioselective and asymmetric allylic alkylation of azlactones with MBH carbonates has been developed with chiral oxalamide-phosphine ligands. The corresponding reaction afforded a range of optically active γ-arylidenyl glutamic acid derivatives bearing an α-chiral quaternary stereocenter in good yields with excellent linear regio- and high enantioselectivity. This protocol furnishes an alternative approach for the construction of enantio-enriched unnatural α-amino acid derivatives.

Multienzymatic Cascade for Synthesis of Hydroxytyrosol via Two-Stage Biocatalysis.

Hydroxytyrosol, a naturally occurring compound with antioxidant and antiviral activity, is widely applied in the cosmetic, food, and nutraceutical industries. The development of a biocatalytic approach for producing hydroxytyrosol from simple and readily accessible substrates remains a challenge. Here, we designed and implemented an effective biocatalytic cascade to obtain hydroxytyrosol from 3,4-dihydroxybenzaldehyde and l-threonine via a four-step enzymatic cascade composed of seven enzymes. To prevent cross-reactions and protein expression burden caused by multiple enzymes expressed in a single cell, the designed enzymatic cascade was divided into two modules and catalyzed in a stepwise manner. The first module (FM) assisted the assembly of 3,4-dihydroxybenzaldehyde and l-threonine into (2S,3R)-2-amino-3-(3,4-dihydroxyphenyl)-3-hydroxypropanoic acid, and the second module (SM) entailed converting (2S,3R)-2-amino-3-(3,4-dihydroxyphenyl)-3-hydroxypropanoic acid into hydroxytyrosol. Each module was cloned into Escherichia coli BL21 (DE3) and engineered in parallel by fine-tuning enzyme expression, resulting in two engineered whole-cell catalyst modules, BL21(FM01) and BL21(SM13), capable of converting 30 mM 3,4-dihydroxybenzaldehyde to 28.7 mM hydroxytyrosol with a high space-time yield (0.88 g/L/h). To summarize, the current study proposes a simple and effective approach for biosynthesizing hydroxytyrosol from low-cost substrates and thus has great potential for industrial applications.

A Class of Enantiomerically Pure Bis-oxamide Palladium Complexes: Modular Synthesis via Domino C(sp2)-H Bond Arylation and Photophysical Property.

A one-pot, five-step domino reaction was developed for the arylation of bis-oxamides derived from optically pure 1,2-diphenylethylenediamine, leading to the formation of a series of chiral bis-oxalamide palladium(II) complexes bearing tetraaryl-conjugated substituents in good yields. In addition, these palladium(II) complexes exhibited perceptible blue fluorescence under ultraviolet light irradiation.

COAP/Pd-Catalyzed Linear Asymmetric Allylic Alkylation for Optically Active 3,3-Disubstituted Oxindole Derivatives with a Four-Carbon Amino Side Chain.

An asymmetric linear selective allylic alkylation of vinylaziridines with 3-aryl oxindoles has been developed by using a chiral oxamide-phosphine (COAP-Bn-OMe-p)/palladium complex in methanol, which furnished a wide variety of 3,3-disubstituted oxindole derivatives in good yields with excellent regio- and enantioselectivities.

A hybrid intelligent controller for a twin rotor MIMO system and its hardware implementation.

This paper presents a fuzzy PID control scheme with a real-valued genetic algorithm (RGA) to a setpoint control problem. The objective of this paper is to control a twin rotor MIMO system (TRMS) to move quickly and accurately to the desired attitudes, both the pitch angle and the azimuth angle in a cross-coupled condition. A fuzzy compensator is applied to the PID controller. The proposed control structure includes four PID controllers with independent inputs in 2-DOF. In order to reduce total error and control energy, all parameters of the controller are obtained by a RGA with the system performance index as a fitness function. The system performance index utilized the integral of time multiplied by the square error criterion (ITSE) to build a suitable fitness function in the RGA. A new method for RGA to solve more than 10 parameters in the control scheme is investigated. For real-time control, Xilinx Spartan II SP200 FPGA (Field Programmable Gate Array) is employed to construct a hardware-in-the-loop system through writing VHDL on this FPGA.