The geometry of the carbanionic moiety influences the non-induced diastereoselectivity of the [2,3]-Wittig rearrangement of lithiated diallyl ethers
作者:Dirk Goeppel、Ingo Münster、Reinhard Brückner
DOI:10.1016/s0040-4020(01)90391-6
日期:1994.3
diallyl ethers 10, from the vinylogous O,S-acetals 13, and from the O,S-acetals 14 by treatment with nBuLi (in the case of 10) or with lithium naphthalenide (in the case of 13 and 14). [2,3]-Wittig rearrangements ensued whose syn,anti-selectivity was studied.
New Strategic Reactions for Organic Synthesis: Catalytic Asymmetric C−H Activation α to Oxygen as a Surrogate to the Aldol Reaction
作者:Huw M. L. Davies、Rohan E. J. Beckwith、Evan G. Antoulinakis、Qihui Jin
DOI:10.1021/jo034533c
日期:2003.8.1
The C-H activation of silyl ethers by means of rhodium carbenoid-induced C-H insertion represents a very direct method for the stereoselective synthesis of silyl-protected beta-hydroxy esters. The reaction can proceed with very high regio-, diastereo-, and enantioselectivity and represents a surrogate to the aldol reaction. The reaction is catalyzed by the rhodium prolinate complex Rh(2)(S-DOSP)(4)
In the presence of catalytic to stoichiometric amounts of trimethylsilyl triflate, 1:1:1 mixtures of silyl ethers, phenyl(trimethylsilyl)sulfide, and aldehydes give O,S-acetals in fair to good yields.
Main Group-Catalyzed Cationic Claisen Rearrangements via Vinyl Carbocations
作者:Chloe G. Williams、Sepand K. Nistanaki、Krista Dong、Woojin Lee、Kendall N. Houk、Hosea M. Nelson
DOI:10.1021/acs.orglett.4c00837
日期:2024.6.14
interception of vinyl carbocations with allylethers. The reaction utilizes commercially available borate salts as catalysts and is effective at constructing sterically hindered C–C bonds. The reaction mechanism is studied experimentally and computationally to support a charge-accelerated [3,3] rearrangement of a silyloxonium cation. Our reaction is also applied to the highlystereoselectivesynthesis of fully