A Direct and Stereoretentive Synthesis of Amides from Cyclic Alcohols
作者:Deboprosad Mondal、Luca Bellucci、Salvatore D. Lepore
DOI:10.1002/ejoc.201101165
日期:2011.12
Chlorosulfites prepared in situ using thionyl chloride react with nitrile complexes of titanium (IV) fluoride to give a one-pot conversion of alcohols into amides. For the first time, amides are obtained from cyclic alcohols with stereoretention. Critical to the design of these new Ti(IV) reactions has been the use of little explored Ti(IV) nitrile complexes which are thought to chelate chlorosulfites
Carre; Libermann, Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences, 1933, vol. 196, p. 1419
作者:Carre、Libermann
DOI:——
日期:——
Reinvestigation of the SNi reaction. The ionization of chlorosulfites
作者:Peter R. Schreiner、Paul v. R. Schleyer、Richard K. Hill
DOI:10.1021/jo00062a028
日期:1993.5
The decomposition of alkyl chlorosulfites (ROSOCl) has been investigated both computationally and experimentally. Semiempirical (AM1 and PM3) as well as ab initio (HF/3-21G(*), HF/6-31G*, and MP2(full)/6-31G*//MP2(full)/6-31G*) methods were employed, and the results were confirmed experimentally by NMR spectroscopy. The computations indicated that certain alkyl sulfinyl cations (ROSO+) are stable and might be involved in the decomposition of chlorosulfites. Detection of these ions by H-1 and C-13 NMR spectroscopy in polar solvents such as acetone-d6 and acetonitrile-d3 as well as kinetic studies allowed important conclusions to be drawn about the mechanistic details of the S(N)i reaction. We conclude that primary alkyl chlorosulfites ionize to yield a sulfinyl cation (ROSO+) and Cl-, whereas tertiary chlorosulfites preferentially give a carbenium ion and a chlorosulfinyl anion (OSOCl-). The generation of these ion pairs is facilitated in polar solvents where the rates of decomposition of chlorosulfites are largely accelerated. The decomposition of neopentyl chlorosulfite without rearrangement and the substitution at the bridgehead position of 7,7-dimethylbicyclo[2.2.1]-heptyl 1-chlorosulfite show that the loss Of SO2 from ROSO+ must be accompanied by the attack of the chloride ion from the front side.