Diastereoselective synthesis of propargylic fluorides and its application in preparation of monofluorinated sugar
摘要:
An effective method to diastereoselectively synthesize enantioenriched propargylic fluorides was developed via S(N)1 type reaction of DAST participated dehydroxy-fluorination of diastereomeric propargylic alcohol cobalt carbonyl complexes. A serious of propargylic fluorides can be prepared by this approach in good yields with moderate to high diastereoselectivities. To demonstrate the application of this approach in synthesis, monofluorinated sugar 12, an important and versatile building block, was prepared in an efficient manner. (C) 2010 Elsevier Ltd. All rights reserved.
Diastereoselective synthesis of propargylic fluorides and its application in preparation of monofluorinated sugar
摘要:
An effective method to diastereoselectively synthesize enantioenriched propargylic fluorides was developed via S(N)1 type reaction of DAST participated dehydroxy-fluorination of diastereomeric propargylic alcohol cobalt carbonyl complexes. A serious of propargylic fluorides can be prepared by this approach in good yields with moderate to high diastereoselectivities. To demonstrate the application of this approach in synthesis, monofluorinated sugar 12, an important and versatile building block, was prepared in an efficient manner. (C) 2010 Elsevier Ltd. All rights reserved.
A range of dehydroxyfluorination reagents was reacted with separate diastereoisomers of a chiral allylic alcohol to explore both the regio- and stereoselectivity ratios of direct versus allylic fluorination. The allylic alcohol stereoisomers gave the same predominant fluorinated diastereoisomer indicating that the reaction proceeds with a significant S(N)1 component via an allylic carbocation intermediate, which is quenched by fluoride ion, predominantly from the least hindered face. None of the reagents displayed very high regio- or stereoselectivity, although in all cases the allylic fluorination products predominated. (c) 2009 Elsevier B.V. All rights reserved.
Diastereoselective synthesis of propargylic fluorides and its application in preparation of monofluorinated sugar
作者:Shilu Fan、Chun-Yang He、Xingang Zhang
DOI:10.1016/j.tet.2010.04.078
日期:2010.7
An effective method to diastereoselectively synthesize enantioenriched propargylic fluorides was developed via S(N)1 type reaction of DAST participated dehydroxy-fluorination of diastereomeric propargylic alcohol cobalt carbonyl complexes. A serious of propargylic fluorides can be prepared by this approach in good yields with moderate to high diastereoselectivities. To demonstrate the application of this approach in synthesis, monofluorinated sugar 12, an important and versatile building block, was prepared in an efficient manner. (C) 2010 Elsevier Ltd. All rights reserved.