Tetra-substituted Amino Aluminum Phthalocyanine as a New Red-region Fluorescent Substrate for Horseradish Peroxidase Based Enzyme-linked Immunosorbent Assay

The use of tetra-substituted ammo aluminum phthalocyanine (TAAIPc) as a new red-region fluorescent substrate for horseradish peroxidase (HRP)-based enzyme-linked immunosorbent assay was investigated. TAAIPc displayed an excitation maximum at 610 nm and emission maximum at 678 nm in a strong acidic medium. In the presence of HRP, trace amounts of H2O2 could rapidly and significantly react with TAAIPc, thus quenching the fluorescence of TAAIPc. The Michaelis-Menten parameters Km and Vmax were measured to be 2.82 × 10?6 mol/L?1 and 6.0 × 10?9 mol·L?1, respectively. In this paper, TAAIPc was used in an HRP-based enzyme-linked immunosorbent assay (ELISA) of α-fetoprotein (AFP) in human serum with satisfactory results. AFP could be determined in the concentration range of 0.5–200 ng/mL with a detection limit of 0.2 ng/mL, which was close to that of radioimmunoassay. The advantage of proposed method was strongly minimizing the interference resulting from background fluorescence or scattering light and had a high analytical sensitivity.

Enantioselective synthesis of tetrasubstituted allenes via addition/arylation tandem reaction of 2-activated 1,3-enynes

We report the development of a new class of multifunctional chiral guanidine/Pd(0)catalyst system for 1,4-addition/arylation tandem reaction.A variety of tetra-substituted allenes were readily accessible from three-component“one-pot”transformations of acyclic or cyclic 2-activated 1,3-enynes,malonates and halobenzenes under mild reaction conditions.High levels of yield and enantioselectivity were achieved in the construction of stereogenic center and axis using readily available acyclic guanidineamides.The mechanistic studies suggest that the guanidine/Pd(0)collaboration has obvious synergism to both base-dominated conjugate addition,and Pd(0)-dominated Heck-type reaction.

Photoinduced Merging with Copper-or Nickel-Catalyzed 1,4-Cyanoalkylarylation of 1,3-Enynes to Access Multiple Functionalizatized Allenes in Batch and Continuous Flow

A three-component reaction of 1,3-enynes and cyclobutanone oxime esters in the presence of aryl boronic acids or organozinc reagents via the photoredox/copper or photoredox/nickel catalysis has been established.This redox-neutral 1,4-cyanoalkylarylation reaction has demonstrated mild condition,high catalytic reactivity and wide functional group compatibility,allowing access to a variety of functionalized tetra-substituted allene derivatives with high chemo-and regioselectivity.Moreover,using photocatalytic continuous flow technique to promote this process would result in increased yields(70%in flow vs.61%in batch),reduced reaction times(7 min in flow vs.6 h in batch),and easy scale-up(upgrade to gram scale),showcasing its potential as a synthetic platform.