- Calcium-catalyzed direct amination of π-activated alcohols
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A calcium-catalyzed direct amination of π-activated alcohols with different nitrogen nucleophiles under very mild reaction conditions is presented. The high reactivity of the calcium catalyst allows for an efficient conversion of secondary and tertiary benzylic and allylic as well as tertiary propargylic alcohols. Nitrogen nucleophiles such as carbamates, tosylamides and anilines are readily alkylated at room temperature.
- Haubenreisser, Stefan,Niggemann, Meike
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supporting information; experimental part
p. 469 - 474
(2011/04/16)
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- Chemo- and diastereoselective cyclopropanation of allylic amines and carbamates
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A highly chemo- and diastereoselective protocol for the cyclopropanation of tertiary allylic amines with Shi's carbenoid [CF3CO 2ZnCH2I] is described. The high levels of diastereoselectivity observed in these reactions may be attributed to chelation of the nitrogen atom to the zinc reagent, which then transfers a methylene unit to the syn-face of the olefin. Furthermore, a stereodivergent protocol for the cyclopropanation of a range of allylic carbamates has been developed, which provides access to both diastereoisomers of the corresponding cyclopropanes with very high levels of diastereoselectivity: cyclopropanation with the Wittig-Furukawa reagent [Zn(CH2I)2] proceeds under chelation control to give the corresponding syn-product, whilst reaction with Shi's carbenoid proceeds under steric control to give the corresponding anti-cyclopropane, in >95:5 dr in both cases.
- Csatayová, Kristína,Davies, Stephen G.,Lee, James A.,Ling, Kenneth B.,Roberts, Paul M.,Russell, Angela J.,Thomson, James E.
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p. 8420 - 8440
(2010/12/20)
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- Bismuth-catalyzed intermolecular hydroamination of 1,3-dienes with carbamates, sulfonamides, and carboxamides
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A Bi(OTf)3/Cu(CH3CN)4PF6 system efficiently promoted intermolecular 1:1 hydroamination of 1,3-dienes with various carbamates, sulfonamides, and carboxamides to afford allylic amines in good yield (up to 96%). Re
- Qin, Hongbo,Yamagiwa, Noriyuki,Matsunaga, Shigeki,Shibasaki, Masakatsu
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p. 1611 - 1614
(2007/10/03)
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- A new synthetic method for the preparation of amino sugars through an allyl cyanate-to-isocyanate rearrangement
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A new approach for the synthesis of amino sugars using an allyl cyanate-to-isocyanate rearrangement has been developed. The key feature in this method involves introduction of the nitrogen substituent into the pyranose framework by [3,3] sigmatropic rearrangement of an allyl cyanate. Subsequent functionalization of the allylamine moiety by either hydroxylation or cyclofunctionalization completes the synthesis of two amino sugars, D-perosamine and D-vicenisamine.
- Ichikawa, Yoshiyasu,Osada, Masafumi,Ohtani, Ikuko I.,Isobe, Minoru
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p. 1449 - 1455
(2007/10/03)
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