作者:Alois Fürstner、Melanie Bonnekessel、Jarred T. Blank、Karin Radkowski、Günter Seidel、Fabrice Lacombe、Barbara Gabor、Richard Mynott
DOI:10.1002/chem.200700926
日期:2007.10.26
exquisitely selective ring closing alkyne metathesis reaction (RCAM) catalyzed by the molybdenum tris-amido complex 20 activated in situ with CH2Cl2. The resulting cyclic enyne 76 was subjected to a ruthenium catalyzed trans-hydrosilylation/proto-desilylation tandem. Although [Cp*Ru(MeCN)3]PF6 had previously been recommended as catalyst of choice for trans-hydrosilylation reactions of internal alkynes
Stereoselective Syntheses of the C(1)−C(9) Fragment of Amphidinolide C
作者:Robert H. Bates、J. Brad Shotwell、William R. Roush
DOI:10.1021/ol801852j
日期:2008.10.2
Stereoselective syntheses of the C(1)-C(9) fragments 18 and 28 of amphidinolide C have been developed. The first-generation sequence involves a diastereoselective chelate-controlled [3 + 2]-annulation reaction of 6 and 7, while the second-generation synthesis involves an intramolecular hetero-Michael cyclization of 8.
Enantio- and Diastereoselective Synthesis of <i>N</i>-Acetyl Dihydrotetrafibricin Methyl Ester
作者:Philippe Nuhant、William R. Roush
DOI:10.1021/ja401918r
日期:2013.4.10
methyl ester (34) is described. The synthesis features three enantioselective double allylborationreactions and an intramolecular hydrosilylation/Fleming-Tamao oxidation sequence to establish seven of the hydroxy-bearing stereocenters of 34. Especially noteworthy is the fragment-assembly double allyboration reaction of 2 and 7 using reagent 3, which provides the advanced intermediate 6 with >20:1 diastereoselectivity
Stereoselective Synthesis of γ-Substituted (<i>Z</i>)-Allylic Boranes via Kinetically Controlled Hydroboration of Allenes with 10-TMS-9-borabicyclo[3.3.2]decane
作者:Jeremy Kister、Amy C. DeBaillie、Ricardo Lira、William R. Roush
DOI:10.1021/ja905494c
日期:2009.10.14
Kineticallycontrolled hydroboration of allenes 8 and 14a-d with the readily accessible Soderquist borane 7, which is generated in situ from borohydride 6, constitutes a convenient and preparatively useful method for synthesis of (Z)-gamma-(substituted)allylboranes 9 and 15a-d. These allylboranes undergo highly diastereo- (> or = 90: 10) and enantioselective (typically 89-96% e.e.) allylboration reactions
Enantioselective Synthesis of 1,5-<i>anti</i>- and 1,5-<i>syn</i>-Diols Using a Highly Diastereoselective One-Pot Double Allylboration Reaction Sequence
作者:Eric M. Flamme、William R. Roush
DOI:10.1021/ja028055j
日期:2002.11.1
gamma-boryl-substituted allylborane reagents 4 and 11 were generated in situ by the hydroboration of allenes 3 and 10 with diisopinocampheylborane. The keys to the success of this method are the excellent stereocontrol in the allylboration step leading to 5 and the corresponding substituted methallylboronate derived from 11, the stereospecificity of the subsequent allylborationreaction of the substituted