Photochemical Organocatalytic Regio‐ and Enantioselective Conjugate Addition of Allyl Groups to Enals
作者:Martin Berger、Davide Carboni、Paolo Melchiorre
DOI:10.1002/anie.202111648
日期:2021.12.6
The first catalytic enantioselective conjugateaddition of allyl groups to α,β-unsaturated aldehydes is disclosed. The chemistry exploits the visible-light-excitation of chiral iminium ions to activate allyl silanes towards the formation of allylic radicals, which are then stereoselectively intercepted with high α-regioselectivity, complete chemoselectivity, and moderate to good enantioselectivity
Photochemical reactivity of α-phenyl β,γ-enones. Singlet 1,3-acyl shift, triplet aromatic di-π-methane (DPM) rearrangement and triplet aryl-carbonyl bridging
作者:Margareth J. C. M. Koppes、Peter C. J. Beentjes、Hans Cerfontain
DOI:10.1002/recl.19881070404
日期:——
The photochemistry of the series of α-phenyl β,γ-enones 6–10 has been studied under conditions of both direct (λ 300 nm) and triplet-sensitized irradiation with the aim of determining the reactivity patterns of these “multi”-chromophoric systems.
The Reactivity of Epoxides with Lithium 2,2,6,6-Tetramethylpiperidide in Combination with Organolithiums or Grignard Reagents
作者:David M. Hodgson、Matthew J. Fleming、Steven J. Stanway
DOI:10.1021/jo070291v
日期:2007.6.1
2-disubstituted epoxides in the presence of LTMP to generate alkenes in a completely regio- and highlystereoselective manner. Arylated alkenes, dienes, allylsilanes, and enynes are accessed using this procedure. The methodology is applied in the synthesis of the roller leaf moth pheromone, (3E,5Z)-dodecadienyl acetate. The corresponding reaction without LTMP has also been examined, and a study using deuterated
allylsilanes to functionalized allenes was developed. Thermal decomposition of 1,1-dibromo-2-(silylmethyl)cyclopropanes, which were quantitatively prepared by treatment of allylsilane derivatives with CHBr3/KOtBu, afforded substituted 2-bromo-1,3-butadienes with elimination of bromosilanes. The Pd-catalyzed reaction of the bromodienes with soft nucleophiles gave the allene derivatives. Previously inaccessible
开发了将烯丙基硅烷转化为官能化烯的三步路线。1,1-二溴-2-(甲硅烷基甲基)环丙烷的热分解,通过用CHBr 3 / KO t处理烯丙基硅烷衍生物定量制备Bu,得到取代的2-溴-1,3-丁二烯,并且消除了溴硅烷。溴代双烯与软亲核试剂的钯催化反应生成了丙二烯衍生物。也可以通过该方法制备以前难以获得的三和四取代的烯。
SHIMIZU, NOBUJIRO;IMAZU, SACHIKO;SHIBATA, FUMIHIRO;TSUNO, YUHO, BULL. CHEM. SOC. JAP., 64,(1991) N, C. 1122-1128