给出了溶液中短寿命苯乙烯基的ESR数据。通过用适当的氢化锡对过氧化二叔丁基进行紫外线照射,可在ESR光谱仪的腔中产生自由基。自由基R 3 Sn 。(R = Me,n-Pr,n-Bu)显示出与β-质子相互作用引起的多重峰(a H = 0.30–0.31 mT,g = 2.0160–2.0163),谱线展宽取决于[R 3 SnH]。自由基Ph n Me 3- n Sn 。(n = 1,2)由于甲基质子(a H = 0.30 mT)而仅显示分裂。观察到的线宽显示,一邻,对≲0.05 mT的一米≲0.03 mT的。自由基Ph n Et 3- n Sn。( n = 0–2)没有显示出由于交换收窄效应而引起的亚甲基质子分裂。所述克值减少与增加ñ从2.0163和2.015( Ñ = 0)到2.0023( Ñ = 3),因为在自由基中心从平面构象增加偏差。线展宽和交换变窄作用是由自由基和氢化物分子(之间的快速氢交换引起ķ
First EPR characterisation of the structures and reactivities of α- and β-boryl radicals derived from boronic esters
作者:Andrew McCarroll、John C. Walton、Andrew McCarroll、Roger Nziengui、Bertrand Carboni
DOI:10.1039/a703950f
日期:——
The first EPR observations of carbon-centred radicals with α- and β-boronic ester substitutents indicated moderate thermodynamic stabilisation for the former whereas the latter had an inclination towards β-scission.
Thiophenebutanoic acid derivatives as matrix metalloprotease inhibitors
申请人:Bayer Corporation
公开号:US05854277A1
公开(公告)日:1998-12-29
Inhibitors for matrix metalloproteases, pharmaceutical compositions containing them, and a process for using them to treat a variety of physiological conditions. The compounds of the invention have the generalized formula ##STR1## wherein each T is a substituent group; x is 0, 1, or 2; the group D represents ##STR2## the group R6 represents a variety of possible substituent groups on the carbon chain between D and G, and the group G represents M, ##STR3## in which M represents --CO.sub.2 H, --CON(R.sup.11).sub.2, or --CO.sub.2 R.sup.12 ; and R.sup.13 represents any of the side chains of the 19 noncyclic naturally occurring amino acids.