Synthesis and Crystal Structure of a New Guanidinatoaluminium Complex and Its Utilityin the Meerwein-Ponndorf-Verley Reduction

The treatment of pyrrolidine （C4HsNI-I） with sequentially trimethylaluminum andcarbodiimide CyN--C=NCy in a molar ratio of 1 ：1：1 in the presence of O2 afforded a newguanidinatoaluminurn complex, [{（C4HsN）C（NCy）2}AIMe（/I-OMe）]2 （1）, which was characterizedby elemental analyses, 1H, 13C NMR spectra and single-crystal X-ray diffraction analysis. ComplexI crystallizes in monoclinic, space group P21/c with a = 9.8330（9）, b = 8.5786（8）, c = 24.159（2） A,β= 92.927（2）°, V= 2035.3（3） A3, Dc = 1.141 g cm^-3, F（000） = 768 and μ= 0.110 mm^-l. In addition,complex 1 was used to catalyze the Meerwein-Ponndorf-Verley （MPV） reduction and 1 as apre-catalyst at low catalyst loadings （5 tool%） exhibited good catalytic activity for the reduction ofa series of aldehydes to the corresponding alcohols in good yields （cony. up to 99%）.

Chiral liquid crystals based on pillararene and supramolecular self-assembly-induced chirality amplification

Macrocyclic liquid crystals combine the unique property of liquid crystals and excellent supramolecular assembly ability of macrocyclic compounds.It is a significant challenge to make rational use of the advantages of macrocyclic compounds to prepare new macrocyclic mesogens.Pillararenes,a type of macrocycles with rigid pillar-shaped frameworks and easy-tofunctionalize property,are excellent building blocks to fabricate liquid crystal materials.However,the site-selective modification property of pillararene has been rarely exploited to tailor liquid crystal behaviors.Previously reported pillararene-based liquid crystal systems are almost prepared by per-functionalized pillararenes.Herein,we report the regulation of chiral liquid crystal behaviors by different derivatization of pillararene.Lyotropic and thermotropic liquid crystals with different chirality were obtained by self-assembly of pillararene with different numbers of cholesterol groups.The bridge between thermotropic liquid crystal and lyotropic liquid crystal based on pillararene is built.In addition,the chirality of the mesogens can be amplified through supramolecular self-assembly driven by noncovalent interactions.Based on the different liquid crystal behaviors,the optical signal of the pillararene-based chiral liquid crystals was used to fabricate an information encryption system.This work provides a simple strategy to regulate liquid crystal behaviors via pillararene-based mesogens and realizes information encryption through the combination of different types of liquid crystals.

A special o-dialdehyde fluorescent probe simultaneously sensing Hcy,GSH and its application in living cells and zebrafish imaging

The development of fluorescent probes enabling to distinguish Cys,Hcy and GSH has always been a considerable challenge,in particular the distinction of Hcy and other two biothiols,because Hcy has a very similar structure with Cys and a relatively lower concentration in living organisms.In this work,a special o-dialdehyde fluorescent probe,quinoline-2,3-dicarboxaldehyde(QDA),has been synthesized and demonstrated superior performance in differentiating detection of Hcy and GSH,which is different from the previous reported o-dialdehyde probes specifically detecting GSH.Furthermore,the probe can selectively distinguish Hcy and GSH from different signal channels in living cells and zebrafish,meaning it has great potential in biological applications.This finding will provide a novel idea for the design of fluorescent probes to distinguish biothiols.

Total syntheses of bupleurynol and its analog

An efficient route to the natural products bupleurynol and its analog（RB-2）,isolated from Bupleuri Radix,was established based on versatile intermediate（15）.In this synthetic route,Sonogashira and CadiotChodkiewicz coupling as well as Julia-Kocienski olefination are utilized as key steps.The highly efficient synthetic route provides opportunities to explore the biological behavior of bupleurynol and RB-2.

N,N,O-Tridentate One-dimensional Methyl-bridged Heterobimetallic Complex: Synthesis, Crystal Structure and Catalytic Activity

The sequential reaction of the N,N,O-tridentate ligand HOC(CH2)5CH2N(Me)CH2CH2NMe2(LH)in diethyl ether with AlEtCl2 and MeLi afforded a lithium-aluminum complex containing a polymeric structure of one-dimensional chain[{-LiOC(CH2)5CH2N(Me)CH2CH2NMe2}AlMe2CH3-}n](1),which was characterized by 1H,13C NMR spectra,elemental analyses and single-crystal X-ray diffraction analysis.Complex 1 crystallizes in triclinic,space group P1 with a=10.526(3),b=10.949(3),c=17.799(4)?,β=76.211(11)°,V=1915.3(8)?3,Dc=1.014 g·cm–3,F(000)=648 andμ=0.104 mm–1.In addition,the heterobimetallic complex 1 was used to catalyze the Meerwein-Ponndorf-Verley(MPV)reaction and exhibited excellent catalytic activities in good yield(up to 97%).