Search

The diacetate complexes trans -[Ru(κ 1 -OAc) 2 (PPh 3 ) 2 (NN)] (NN = ethylenediamine (en) ( 1 ), 2-(aminomethyl)pyridine (ampy) ( 2 ), 2-(aminomethyl)pyrimidine (ampyrim) ( 3 )) have been isolated in 76-88% yield by reaction of [Ru(κ 2 -OAc) 2 (PPh 3 ) 2 ] with the corresponding nitrogen ligands. The ampy-type derivatives 2 and 3 undergo isomerization to the thermodynamically most stable cationic complexes [Ru(κ 1 -OAc)(PPh 3 ) 2 (NN)]OAc ( 2a and 3a ) and cis -[Ru(κ 1 -OAc) 2 (PPh 3 ) 2 (NN)] ( 2b and 3b ) in methanol at RT. The trans -[Ru(κ 1 -OAc) 2 (P 2 ) 2 ] (P 2 = dppm ( 4 ), dppe ( 5 )) compounds have been synthesized from [Ru(κ 2 -OAc) 2 (PPh 3 ) 2 ] by reaction with the suitable diphosphine in toluene at 95 °C. The complex cis -[Ru(κ 1 -OAc) 2 (dppm)(ampy)]( 6 ) has been obtained from [Ru(κ 2 -OAc) 2 (PPh 3 ) 2 ] and dppm in toluene at reflux and reaction with ampy. The derivatives trans -[Ru(κ 1 -OAc) 2 P 2 (NN)] ( 7 - 16 ; NN = en, ampy, ampyrim, 8-aminoquinoline; P 2 = dppp, dppb, dppf, ( R )-BINAP) can be easily synthesized from [Ru(κ 2 -OAc) 2 (PPh 3 ) 2 ] with a diphosphine and treatment with the NN ligands at RT. Alternatively these compounds have been prepared from trans -[Ru(OAc) 2 (PPh 3 ) 2 (NN)] by reaction with the diphosphine in MEK at 50 °C. The use of ( R )-BINAP affords trans -[Ru(κ 1 -OAc) 2 (( R )-BINAP)(NN)] (NN = ampy ( 11 ), ampyrim ( 15 )) isolated as single stereoisomers. Treatment of the ampy-type complexes 8 - 15 with methanol at RT leads to isomerization to the cationic derivatives [Ru(κ 2 -OAc)P 2 (NN)]OAc ( 8a - 15a ; NN = ampy, ampyrim; P 2 = dppp, dppb, dppf, ( R )-BINAP). Similarly to 2 , the dipivalate trans -[Ru(κ 1 -OPiv) 2 (PPh 3 ) 2 (ampy)] ( 18 ) is prepared from [Ru(κ 2 -OPiv) 2 (PPh 3 ) 2 ] ( 17 ) and ampy in CHCl 3 . The pincer acetate [Ru(κ 1 -OAc)(CNN OMe )(PPh 3 ) 2 ] ( 19 ) has been synthesized from [Ru(κ 2 -OAc) 2 (PPh 3 ) 2 ] and HCNN OMe ligand in 2-propanol with NEt 3 at reflux. In addition, the dppb pincer complexes [Ru(κ 1 -OAc)(CNN)(dppb)] (CNN = AMTP ( 20 ), AMBQ Ph ( 21 )) have been obtained from [Ru(κ 2 -OAc) 2 (PPh 3 ) 2 ], dppb, and HAMTP or HAMBQ Ph with NEt 3 , respectively. The acetate NN and pincer complexes are active in transfer hydrogenation with 2-propanol and hydrogenation with H 2 of carbonyl compounds at S/C values of up to 10000 and with TOF values of up to 160000 h -1 ., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Fetal endoscopic tracheal occlusion has been proposed as a prenatal intervention to ameliorate congenital diaphragmatic hernia (CDH) prognosis. Tracheal occlusion (TO) prevents pulmonary fluid egress, leading to tissue expansion, reversal of lung hypoplasia, and potential maturation. Fetal lung maturity strongly correlates with amniotic fluid (AF) phospholipidic composition. In this preliminary study, we characterized the AF phospholipidic profile in CDH-induced, TO-treated, and healthy fetal lambs to define the prenatal treatment benefits of TO on lung maturity. CDH induction was performed at 70 days of gestation, TO was carried out at 102 days of gestation, and caesarean section was carried out at 136 days of gestation. AF samples, taken at 102-136 days of gestation, were evaluated using mass spectrometry. The analysis focused on phosphatidylcholines (PCs) and sphingomyelins (SMs). The most abundant phosphatidylcholine species retrieved in healthy AF was POPC [PC(18:1/16:0)], while the level of DPPC [PC(16:0/16:0)] was extremely low at both gestational ages. CDH induction caused a decrease in POPC and many other PCs. A substantial return of some PCs, in particular POPC, PC(34:2) and PC(18:0/16:0), to a more physiological level was prompted by TO. SMs were unaltered. The AF phospholipidic profile could provide prenatal prognostic markers of CDH and possible indices of lung maturation after fetal treatment.

The reaction of oligonucleotides with high molecular weight monomethoxy poly(ethylene glycol)s (MPEGs) has been tested to set up a convenient procedure for the postsynthetic conjugation in solution of biopolymers. A first oligonucleotide was previously modified in 5', using a liquid-phase procedure, with a linker carrying a terminal primary amino group to enhance its nucleophilic reactivity. Two procedures commonly utilized for the activation of the terminal OH groups of the MPEG were evaluated, that is, the reaction with pNO(2)-phenyl chloroformate and with N,N'-disuccinimidyl carbonate. Both water as well as organic solution conditions were employed and compared. In a second test, a 3'-amino modified, commercial 20-mer was also conjugated in a microscale condition to verify the effect of size and concentration of MPEG on the postsynthetic conjugation of these biopolymers under troublesome synthetic conditions.

Long "all-purine" oligonucleotides, up to the 20mer, known to be active as antigene effectors, conjugated to high molecular weight monomethoxy poly(ethylene glycol)s (MPEG)s, were successfully synthesized. Through a liquid-phase, MPEG-supported process, both natural and chimeric sequences containing selected phosphorothioate backbone modifications were obtained, purified, and characterized. To follow their cellular trafficking, a fluorescent probe was linked by soluble supported organic reactions to the 5'-terminus, and the efficiency of the different synthetic procedures for the introduction of a fluorescein moiety was compared. The usefulness of the fluorescent marker was estimated by laser confocal microscopy that ascertains that the MPEG-conjugation enhances the oligonucleotide capacity to cross the cellular membranes and to be accumulated inside the nuclei.