1,1-Carboboration

The use of very electrophilic boranes RB(C(6)F(5))(2) widens the scope of the 1,1-carboboration reaction substantially. Simple terminal alkynes HC≡CR undergo this reaction with the RB(C(6)F(5))(2) reagents rapidly under mild conditions to give high yields of very useful new alkenylborane products. Even internal alkynes RC≡CR undergo 1,1-carboboration with the RB(C(6)F(5))(2) reagents to provide a novel way of carbon-carbon σ-bond activation. Variants of these reactions involving phosphorus substituted alkynes and more complex bisalkynyl main group and transition metal substrates give rise to the formation of very interesting functionalized metallacyclic products upon treatment with RB(C(6)F(5))(2) reagents by means of reaction sequences involving selective 1,1-carboboration steps.     

1,1-Difluorethen-Nickel-Ligand-Komplexe

The use of chelating ligands such as DCPE, BIPY and TMEDA as stabilizing ligands permits the preparation of the novel ligand-Ni complexes of 1,1-difluoroethene. The structures of the 16e complexes were confirmed by ¹H, ¹³C, ¹⁹F and ³¹P NMR spectroscopy. Characteristic properties are described.     

1,1-二苄基-1,1-二硫乙酰腙甲烷类化合物的微波辐射法合成

以1,3-二苯基丙酮为原料,经干燥的H2S和HCl气体反应得二苄基二巯基甲烷(1),在微波辐射条件下,经酯化、肼解,得l,1-二苄基-1,1-二硫乙酰肼(3),再与芳香醛反应,方便地合成了酰腙类新化合物(4a～4n).其结构经IR、1H NMR、MS和元素分析确证.     

The geminal 1,1′-biadamantyl group as a stabilizer of reactive functions : 1,1′-biadamantyldiazomethane, 1,1′-biadamanthylemethylene-iminoxyl and 1,1′-biadamanthylmethylene-iminyl

The syntheses and main properties of the title compounds are described. The diazocompound 3 and the iminoxyl radical 21 proved to be very stable crystalline compounds; the iminyl radical 25 has been characterized by its EPR spectrum and by its typical fragmentation pattern.     

The vibrational analysis of 1,1-dimethylcyclopropane and 1,1-dimethyl-d6-cyclopropane

The i.r. and Raman spectra of 1,1-dimethylcyclopropane and 1,1-dimethyl-d₆-Cyclopropane have been investigated from 100 to 4000 cm⁻¹. Infrared spectra are reported in the solid and vapor states and Raman spectra are reported for all three physical states. Data from the normal and deuterated samples were used for Teller—Redlich product rule calculations as a check on correctness of the vibrational assignments. The 1 ← 0 and 2 ← 0 torsional transitions were observed and the calculated barriers to internal rotation for the solid and vapor states are 3.7 and 3.2 kcal/mole respectively.