catalysed decomposition of vinyldiazocarbonyl compounds in the presence of organosilanes led stereospecifically to the corresponding allylsilanes in good yields. An asymmetric approach has also been considered as well as the extension of the methodology to the synthesis of other allylic systems.
Synthesis of Allylboranes via Cu(I)-Catalyzed B–H Insertion of Vinyldiazoacetates into Phosphine–Borane Adducts
作者:Denis Drikermann、Robert S. Mößel、Walid K. Al-Jammal、Ivan Vilotijevic
DOI:10.1021/acs.orglett.9b04619
日期:2020.2.7
Cu(I) catalysts enable C-B bond formation via direct insertion of vinyldiazoacetates into B-H bonds of borane-phosphine Lewis adducts to form phosphine-protected allylboranes under mild conditions. The resulting allylborane-phosphine Lewis adducts can be used in the diastereoselective allylation of aldehydes directly without the need for removal of the phosphine. The allylation reaction proceeds with
Access to N-Substituted 2-Pyridones by Catalytic Intermolecular Dearomatization and 1,4-Acyl Transfer
作者:Guangyang Xu、Ping Chen、Pei Liu、Shengbiao Tang、Xinhao Zhang、Jiangtao Sun
DOI:10.1002/anie.201812937
日期:2019.2.11
A novel rhodium‐catalyzed dearomatization of O‐substituted pyridines to access N‐substituted 2‐pyridones has been developed. A computational study suggests a mechanism involving the formation of a pyridinium ylide followed by an unprecedented 1,4‐acyl migratory rearrangement from O to C. Furthermore, the chiral dirhodium complexes serve as the catalyst for the asymmetric transformation with excellent
Enantioselective Reactions of Donor/Acceptor Carbenoids Derived from α-Aryl-α-Diazoketones
作者:Justin R. Denton、Huw M. L. Davies
DOI:10.1021/ol802614j
日期:2009.2.19
variety of α-aryl-α-diazo ketones with activated olefins, catalyzed by the adamantyl glycine-derived dirhodium complex Rh2(S-PTAD)4, generates cyclopropyl ketones with high diastereoselectivity (up to >95:5 dr) and enantioselectivity (up to 98% ee). Intermolecular C−H functionalization of 1,4-cyclohexadiene by means of carbenoid-induced C−H insertion was also possible with this type of carbenoid.
金刚烷基甘氨酸衍生的铑络合物Rh 2(S -PTAD)4催化多种α-芳基-α-重氮酮与活化烯烃的反应,生成具有高非对映选择性的环丙基酮(高达> 95:5 dr )和对映选择性(最高98%ee)。这种类胡萝卜素也可能通过类胡萝卜素诱导的CH插入而使1,4-环己二烯分子间的CH官能化。
One-Pot Synthesis of Highly Functionalized Pyridines via a Rhodium Carbenoid Induced Ring Expansion of Isoxazoles
作者:James R. Manning、Huw M. L. Davies
DOI:10.1021/ja803139k
日期:2008.7.1
A concise one-pot synthesis of highlyfunctionalized pyridines has been developed. The first step in the reaction sequence is the formal insertion of rhodium vinylcarbenoids across the N-O bond of isoxazoles. Upon heating, the insertion products undergo a rearrangement to give 1,4-dihydropyridines. DDQ oxidation then affords the corresponding pyridines in 31-84% yield. The process has proven general
已开发出高度官能化吡啶的简洁一锅法合成。反应序列中的第一步是将乙烯基卡宾铑正式插入到异恶唑的 NO 键上。加热后,插入产物发生重排,得到 1,4-二氢吡啶。然后DDQ氧化以31-84%的产率提供相应的吡啶。该过程已被证明适用于一系列类卡宾和异恶唑组分,并代表了合成功能化吡啶的独特断开策略。