The present invention provides methods for reducing induction periods in epoxide-CO
2
copolymerizations. In certain embodiments, the methods include the step of contacting an epoxide with CO
2
in the presence of two catalysts: an epoxide hydrolysis catalyst and an epoxide CO
2
copolymerization catalyst. In another aspect, the invention provides catalyst compositions comprising a mixture of an epoxide hydrolysis catalyst and an epoxide CO
2
copolymerization catalyst.
US9512269B2
申请人:——
公开号:US9512269B2
公开(公告)日:2016-12-06
Convenient Preparation of Alkyl Benzyl Imidodicarbonates, Useful Reagents for the Direct Synthesis of Protected Amines
作者:Leif Grehn、M. Lurdes、S. Almeida、Ulf Ragnarsson
DOI:10.1055/s-1988-27780
日期:——
New mixed alkyl benzyl imidodicarbonates were prepared by reaction of benzyloxycarbonyl isocyanate with appropriate alcohols. This simple procedure also furnished alternative, more convenient routes to dibenzyl and benzyl 9-fluorenylmethyl imidodicarbonates. The substances are of interest as potential Gabriel reagents. Completely selective removal of one of the alkoxycarbonyl groups from the N-atom of the imidodicarbonates was demonstrated in several instances, giving benzyl carbamate or the alternative carbamate.