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
C−H Activation as a Strategic Reaction: Enantioselective Synthesis of 4-Substituted Indoles
作者:Huw M. L. Davies、James R. Manning
DOI:10.1021/ja057768+
日期:2006.2.1
A method is described for the asymmetric synthesis of 4-substitutedindoles from the Rh2(S-DOSP)4-catalyzed decomposition of vinyldiazoacetates in the presence of N-Boc-4-acetoxy-6,7-dihydroindole. The reaction proceeds via a combined C-H activation/Cope rearrangement-elimination mechanism resulting in good yields and very high asymmetric induction.
Combined C–H Functionalization/Cope Rearrangement with Vinyl Ethers as a Surrogate for the Vinylogous Mukaiyama Aldol Reaction
作者:Yajing Lian、Huw M. L. Davies
DOI:10.1021/ja2051155
日期:2011.8.10
selectively undergo the combined C-H functionalization/Cope rearrangement reaction via an s-cis/boat transition state. With chiral dirhodium catalysts, products are generated in a highly diastereoselective and enantioselective fashion. This reaction can be considered as a surrogate to the traditional vinylogousMukaiyamaaldolreaction. Effective kinetic resolution has been achieved, leading to the recovery
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。
Palladium-catalyzed insertion of α-diazocarbonyl compounds for the synthesis of cyclic amino esters
Two different cyclic amino esters are synthesized by palladium-catalyzed cross-coupling reaction of diazoesters with N-substituted-2-iodoanilines. Aryldiazoacetates lead to cyclic α-amino esters with an α-quaternary carbon centre in the presence of CO. Additionally, arylvinyldiazoacetates afford cyclic α,β-unsaturated γ-amino esters.