Synthesis of alkyl nitrones by reaction of aldehyde and ketone oximes with α,β-unstaturated esters in the presence of Lewis acid
摘要:
Reactions of pyridinecarbaldehyde oximes, methyl pyridyl ketone oximes, furfural oxime, cinnamaldehyde oxime, and crotonaldehyde oxime with acrylic and methacrylic acid esters in the presence of a Lewis acid catalyst at room temperature followed the conjugate addition pattern to give the corresponding alkyl nitrones in good yield. The best yields were obtained using a 1: 1 mixture of CdI(2) and BF(3) center dot Bu(2)O as catalyst.
A series of (E)-α-silyl-β-alkoxyvinyl-λ3-iodanes was synthesized from iodosylbenzene, BF3–ether complexes, and terminal ethynylsilanes. The combined use of BF3–OiPr2 and benzyl ethers of primary alcohols (ROBn) allows the chemoselective transfer of primary alkoxy groups (RO) onto the β-position of the terminal ethynylsilanes.
以碘代苯、BF 3 -醚络合物和末端乙炔基硅烷为原料,合成了一系列( E )-α-甲硅烷基-β-烷氧基乙烯基-λ 3 -碘烷。BF 3 –O i Pr 2和伯醇的苄基醚 (ROBn) 的组合使用允许伯烷氧基 (RO) 化学选择性转移到末端乙炔基硅烷的 β 位上。
Improved Procedures for the Generation of Diborane from Sodium Borohydride and Boron Trifluoride
作者:Josyula V. B. Kanth、Herbert C. Brown
DOI:10.1021/ic0000911
日期:2000.4.1
50 degrees C). The byproduct NaBF4 precipitates from the reaction mixture at 25 degrees C as the reaction proceeds. The high-boiling glyme can be conveniently separated from the lower boiling carrier ethers by simple distillation of the latter. On the other hand, diborane was generated very slowly or not generated using the addition of each of six boron trifluoride-etherates (di-n-butyl ether, tert-butyl