Chromium mediated stereoselective synthesis of (Z)-1-fluoro-2-alkenyl alkyl and trialkylsilyl ethers from dibromofluoromethylcarbinyl ethers
摘要:
Reactions of 2,2-dibromo-2-fluoi-oethyl alkyl ethers and dibromofluomethylcarbinyl silyl ethers with CrCl2 and Mn powder provided 2-fluorovinyl alkyl ethers and 1-fluoro-2-alkenyl enol silyl ethers in high yields and in Z selective manner. (c) 2005 Elsevier Ltd. All rights reserved.
Preparation of (Z)-1-fluoro-1-alkenyl carboxylates, carbonates and carbamates through chromium mediated transformation of dibromofluoromethylcarbinyl esters and the reactivity as double acyl group donors
CrCl2/Mn-mediated transformation of various dibromofluoromethylcarbinyl esters including carboxylates, carbonates and carbamates provided 1-fluoro-1-alkenyl esters via [2,3]-sigmatropic rearrangement of ester group. Reaction proceeded by using CrCl2/Mn system under mild conditions (in THF at room temperature) to give 1-fluoro-1-alkenyl esters in good yield with an excellent Z selective manner. 1-Fluoro-1-alkenyl
Reactions of 2,2-dibromo-2-fluoi-oethyl alkyl ethers and dibromofluomethylcarbinyl silyl ethers with CrCl2 and Mn powder provided 2-fluorovinyl alkyl ethers and 1-fluoro-2-alkenyl enol silyl ethers in high yields and in Z selective manner. (c) 2005 Elsevier Ltd. All rights reserved.