Generation and electrophilic substitution reactions of 3-lithio-2-methyleneaziridines
摘要:
2-Methyleneaziridinyl anions can be produced by selective deprotonation of the parent aziridine at C-3 using sec-BuLi/TMEDA. Subsequent reaction with a wide variety of electrophiles including MeI, ICH2CH2CH2CH2Cl, PhCH2Br, allyl bromide, Me3SiCl, Bu3SnCl, PhCHO and Ph2CO provides the corresponding C-3 substituted derivatives in moderate to good yields (43-91%). In the case of homochiral methyleneaziridines bearing an (S)-alpha-methylbenzyl group on nitrogen, high levels of diastereocontrol (up to 90%de) can be achieved in this lithiation/alkylation sequence. (c) 2006 Elsevier Ltd. All rights reserved.
Lewis acid promoted intramolecular (3 + 2) ‘cycloadditions’ of methyleneaziridines with alkene and alkyne acceptors
作者:Karen Griffin、Cyril Montagne、Cam Thuy Hoang、Guy J. Clarkson、Michael Shipman
DOI:10.1039/c1ob06578e
日期:——
2-Methyleneaziridines can be tethered to a variety of alkene or alkyne acceptors through the saturated carbon of the heterocyclic ring by application of a simple lithiation/alkylation sequence (8 examples, 31–59%). Treatment of the resultant alkene bearing substrates with BF3·OEt2 leads to cis-octahydrocyclopenta[c]pyrroles in which up to four contiguous stereocentres are created in a diastereocontrolled
Rapid generation of molecular complexity using ‘sequenced’ multi-component reactions: one-pot synthesis of 5,5′-disubstituted hydantoins from methyleneaziridines
作者:Cyril Montagne、Jason J. Shiers、Michael Shipman
DOI:10.1016/j.tetlet.2006.10.135
日期:2006.12
2-Methyleneaziridines can be transformed into 5,5′-disubstituted hydantoins in moderate to good yield (48–75%) via a ‘one-pot’ process that brings together up to six components in an orchestrated way.
A Lewis Acid Catalyzed Intramolecular [4+3] Cycloaddition Route to Polycyclic Systems That Contain a Seven-Membered Ring
作者:Gildas Prié、Natacha Prévost、Heather Twin、Stephanie A. Fernandes、Jerome F. Hayes、Michael Shipman
DOI:10.1002/anie.200461084
日期:2004.12.3
Generation and electrophilic substitution reactions of 3-lithio-2-methyleneaziridines
作者:Cyril Montagne、Natacha Prévost、Jason J. Shiers、Gildas Prié、Sabitur Rahman、Jerome F. Hayes、Michael Shipman
DOI:10.1016/j.tet.2006.06.083
日期:2006.9
2-Methyleneaziridinyl anions can be produced by selective deprotonation of the parent aziridine at C-3 using sec-BuLi/TMEDA. Subsequent reaction with a wide variety of electrophiles including MeI, ICH2CH2CH2CH2Cl, PhCH2Br, allyl bromide, Me3SiCl, Bu3SnCl, PhCHO and Ph2CO provides the corresponding C-3 substituted derivatives in moderate to good yields (43-91%). In the case of homochiral methyleneaziridines bearing an (S)-alpha-methylbenzyl group on nitrogen, high levels of diastereocontrol (up to 90%de) can be achieved in this lithiation/alkylation sequence. (c) 2006 Elsevier Ltd. All rights reserved.