Stereoselective reductions of N-Boc-hexahydro-1H-indolin-5(6H)-ones
作者:Michael A. Brodney、Marcus L. Cole、Jamie A. Freemont、Stella Kyi、Peter C. Junk、Albert Padwa、Andrew G. Riches、John H. Ryan
DOI:10.1016/j.tetlet.2007.01.078
日期:2007.3
stereoselectivity of reduction of the enamide moiety of N-Boc-hexahydro-1H-indolin-5(6H)-ones. Under ionic reduction conditions (triethylsilane/trifluoroaceticacid) the enamide group of 3a-methyl-N-Boc-hexahydro-1H-indolin-5(6H)-one was reduced to afford exclusively a cis ring-fused product. For the 3a-phenyl substituted analogue more forcing conditions (sodiumcyanoborohydride at pH 2–2.5) were required
Enantioselective Claisen Rearrangements with a Hydrogen-Bond Donor Catalyst
作者:Christopher Uyeda、Eric N. Jacobsen
DOI:10.1021/ja803370x
日期:2008.7.1
m ion associated with the noncoordinating BArF counterion is shown to be an effective catalyst for the [3,3]-sigmatropic rearrangement of a variety of substitutedallylvinylethers. Highly enantioselective catalytic Claisenrearrangements of ester-substituted allylvinylethers are then documented using a new C2-symmetric guanidinium ion derivative.
Development of an Intramolecular Aryne Ene Reaction and Application to the Formal Synthesis of (±)-Crinine
作者:David A. Candito、Dennis Dobrovolsky、Mark Lautens
DOI:10.1021/ja306881u
日期:2012.9.19
A general and high yielding annulation strategy for the synthesis of various carbo- and heterocycles, based on an intramolecular aryne ene reaction is described. It was found that the geometry of the olefin is crucial to the success of the reaction, with exclusive migration of the trans-allylic-H taking place. Furthermore, the electronic nature of the aryne was found to be important to the success