Synthesis and characterization of boronates derived from non-symmetric amino-bis-phenols

Encapsulation of the BeII Cation: Spectroscopic and Computational Study

“…Condensations for the alkyl-linked 1a , 1b , and 1f required 30 min stirring at RT, while the aryl-linked 1e required 6 h, and 1c – d were stirred at RT for 7 days. The secondary amines 1a , 1b , 1c ,and 1e are known compounds, and characterization data agreed with the literature, while 1d and 1f had not been previously reported and were therefore fully characterized. The final tertiary amines 2a – f were synthesized in 39–69% yields by refluxing the appropriate secondary amine 1a – f , 2-chloromethyl-4-nitrophenol, and triethylamine in chloroform for 2 h (Scheme (ii)(a)), the carboxylic acid on 1f was isolated by heating the methyl ester in hydrochloric acid (Scheme (ii)(b)).…”

Preparation and Diels–Alder/Cross Coupling Reactions of New 2-Boron-Substituted 1,3-Dienes

“…When their 11 B NMR spectra were obtained, diethanolamine boronate-1,3-butadiene ( 3 ) (δ10.08, (CD 3 ) 2 SO); δ10.46, (CDCl 3 )) was found to have a stronger N–B bond than N-methyl diethanolamine boronate-1,3-butadiene ( 4 ) (δ11.31, (CD 3 ) 2 SO; δ11.38, CDCl 3 ) (these 11 B NMR chemical shifts are similar to other reported diolamine boronates in (CD 3 ) 2 SO) . When the temperature was raised gradually to 60 °C, there was only one boron peak in the diethanolamine boronate-1,3-butadiene ( 3 ) spectrum, but an extra small peak appears (δ10.43, (CD 3 ) 2 SO) in N-methyl diethanolamine boronate-1,3-butadiene ( 4 ), which is consistent with some B–N bond dissociation (accompanied most likely by residual water coordination) at higher temperature .…”

A new ONO3− trianionic pincer ligand with intermediate flexibility and its tungsten alkylidene and alkylidyne complexes

“…Multi-gram quantities of proligand 1 are accessible from readily available starting materials through a straightforward condensation reaction to generate first an imine intermediate, followed by reduction. In a single step, without need for further purification, treating 2-amino-4,6-di-tert-butylphenol [12][13][14][15] with 3,5-di-tert-butyl-2-hydroxybenzaldehyde [16][17][18] provides the imine, 2,4-di-tert-butyl-6-((3,5-di-tert-butyl-2-hydroxybenzylidene)amino)phenol, [19][20][21][22][23] (Scheme 1). Treating the imine, isolated as a pale yellow microcrystalline solid, with excess sodium borohydride 21,24 provides the corresponding secondary amine and the proligand 1 as the hydrochloride salt 1•HCl as a pale pink solid.…”

“…THF-d 8 (Cambridge Isotopes) was used as received. ( t BuO) 3 WuC t Bu, 2,61 2-amino-4,6-di-tert-butylphenol, [12][13][14][15] 3,5-di-tert-butyl-2-hydroxybenzaldehyde, [16][17][18] 2,4-di-tert-butyl-6-((3,5-di-tert-butyl-2-hydroxybenzylidene)amino)phenol, [19][20][21][22][23] and Ph 3 PvCH 2 36 were prepared according to published procedures. All other reagents were purchased from commercial vendors and used without further purification.…”