Process for producing carbamoyl substituted penams and carbamoyl
申请人:Bristol-Myers Company
公开号:US04310459A1
公开(公告)日:1982-01-12
Penicillin sulfoxide esters are reacted with an isocyanate to produce the corresponding (substituted)-2-carbamoyloxymethylpenam, the corresponding (substituted)-3-carbamoyloxycepham or the corresponding 3-methylcephem. The 6- or 7-side-chain of these products may be cleaved to give the corresponding 6-amino (penams) or 7-amino (cephams and cephems) compounds, and the latter may be reacylated to produce different 6-acyl-2-carbamoyloxymethyl penams, 7-acyl-3-carbamoyloxy cephams and 7-acyl-3-methylcephems. The substituent groups may be removed from the (substituted-2-carbamoyloxypenams or the (substituted)-3-carbamoyloxycephams to give the corresponding free 2-carbamoyloxymethylpenams or 3-carbamoyloxycephams, respectively.
Me3Si−X (X=CN, N3, OCN, and SCN) was treated with the Lewis acids GaCl3 and B(C6F5)3 in toluene yielding the desired adducts Me3Si−X→GaCl3 and Me3Si−X→B(C6F5)3. All synthesized adducts were isolated and completely characterized including single crystal structure elucidations. The different structures, thermodynamics of formation and charge transfer effects are discussed on the basis of experimental
用甲苯中的路易斯酸GaCl 3和B(C 6 F 5)3处理Me 3 Si-X(X = CN,N 3,OCN和SCN),得到所需的加合物Me 3 Si-X→GaCl 3和Me 3 Si-X→B(C 6 F 5)3。分离了所有合成的加合物,并进行了完整表征,包括单晶结构阐明。在实验和理论数据的基础上讨论了不同的结构,形成的热力学和电荷转移效应。
Redistribution equilibria involving fluoro and azido groups on the dimethylsilicon moiety
作者:Herbert Müller、John R. Van Wazer
DOI:10.1016/s0022-328x(00)92952-8
日期:1970.7
Equilibrium constants are reported for scrambling of the fluoro and azido groups with chloro, cyanato, methoxyl, methylthio, and dimethylamino groups on the dimethylsilicon moiety. The ΔF° values obtained from these constants show that fluorine lies first in the halogen series (e.g. F, Cl, Br) with respect to exchange with various other substituents and that the azido groups acts as a pseudohalide