C=C双键与分子氧的氧化裂解产生羰基化合物是化学和药物合成中的一个重要转化。在自然界中,含有第一排过渡金属的酶,特别是血红素和非血红素铁依赖性酶,在环境条件下很容易激活 O 2并以极其精确的方式氧化裂解 C=C 键。然而,该反应对合成化学家来说仍然具有挑战性。只有少数已知的合成金属催化剂允许在 O 2大气压下氧化裂解烯烃,很少有人知道催化未活化烯烃的裂解。在这项工作中,我们描述了一种光驱动、Mn 催化的协议,用于在 1 个大气压的 O 2下将烯烃选择性氧化为羰基化合物。首次使用第一排生物相关金属催化剂,在清洁、温和的条件下,可以将芳香族和各种未活化的脂肪族烯烃氧化成酮和醛。此外,该协议显示出非常好的功能组耐受性。机理研究表明,Mn-oxo 物种,包括不对称的混合价双 (μ-oxo)-Mn(III,IV) 络合物,参与氧化,溶剂甲醇参与 O 2活化,导致oxo 物种的形成。
C=C双键与分子氧的氧化裂解产生羰基化合物是化学和药物合成中的一个重要转化。在自然界中,含有第一排过渡金属的酶,特别是血红素和非血红素铁依赖性酶,在环境条件下很容易激活 O 2并以极其精确的方式氧化裂解 C=C 键。然而,该反应对合成化学家来说仍然具有挑战性。只有少数已知的合成金属催化剂允许在 O 2大气压下氧化裂解烯烃,很少有人知道催化未活化烯烃的裂解。在这项工作中,我们描述了一种光驱动、Mn 催化的协议,用于在 1 个大气压的 O 2下将烯烃选择性氧化为羰基化合物。首次使用第一排生物相关金属催化剂,在清洁、温和的条件下,可以将芳香族和各种未活化的脂肪族烯烃氧化成酮和醛。此外,该协议显示出非常好的功能组耐受性。机理研究表明,Mn-oxo 物种,包括不对称的混合价双 (μ-oxo)-Mn(III,IV) 络合物,参与氧化,溶剂甲醇参与 O 2活化,导致oxo 物种的形成。
Csp–Csp<sup>3</sup> Bond Formation via Iron(III)-Promoted Hydroalkynylation of Unactivated Alkenes
作者:Yangyong Shen、Bo Huang、Jing Zheng、Chen Lin、Yu Liu、Sunliang Cui
DOI:10.1021/acs.orglett.7b00499
日期:2017.4.7
An iron(III)-promoted hydroalkynylation of unactivated alkenes toward Csp–Csp3 bond formation has been developed. Various alkenes, including mono-, di-, and trisubstituted alkenes, could all smoothly convert to structural diversified alkynes in this chemoselective protocol. Additionally, the scalability was unraveled and the further divergent transformations of products were conducted to demonstrate
Conjugate addition of allylic groups to α,β-unsaturated carbonyl compounds via (η3-allyl)Fe(CO)2NO complexes
作者:Keiji Itoh、Saburo Nakanishi、Yoshio Otsuji
DOI:10.1016/0022-328x(94)80122-3
日期:1994.6
complexes undergo conjugateaddition to α,β-unsaturatedcarbonylcompounds to give the corresponding δ,ϵ-unsaturated carbonylcompounds in good yields. The reaction of (η3-1-or 2-trimethylsiloxyallyl) Fe(CO)2NO complexes with α,β-unsaturated ketones affords 1,6- or 1,5-diketones, respectively. (η3-1-Acetonylallyl)Fe(CO)2NO complexes also react with α,β-unsaturatedcarbonylcompounds to give 1,8-dicarbonyl
Stereoselective Synthesis of Substituted Oxocene Cores by Lewis Acid Promoted Cyclization
作者:Arun K. Ghosh、Anthony J. Tomaine、Kelsey E. Cantwell
DOI:10.1021/acs.orglett.5b03411
日期:2016.2.5
Substituted oxocene derivatives have been synthesized by Lewis acid catalyzed reactions of ε-hydroxyalkene and substituted aromatic aldehydes. The Cu(OTf)2-bis-phosphine catalyzed reaction typically provides substituted dihydropyran derivatives through an olefin migration followed by a Prins cyclization. The corresponding reaction catalyzed by TMSOTf or BF3·OEt2 provided eight-membered cyclic ethers
Unconventional type of allylation reaction at the β-position of ketone carbonyl has been developed based on the β-metallo ketone strategy: treatment of siloxycyclopropanes 1 with allylic chlorides 2 in the presence of silver fluoride results in the effective formation of δ, ε-unsaturated ketones 4.
Cu(II)-Catalyzed Olefin Migration and Prins Cyclization: Highly Diastereoselective Synthesis of Substituted Tetrahydropyrans
作者:Arun K. Ghosh、Daniel R. Nicponski
DOI:10.1021/ol2016675
日期:2011.8.19
an appropriate bisphosphine ligand have been shown to effectively catalyze the formation of substituted tetrahydropyrans via a sequential olefin migration and Prins-type cyclization. This methodology provides convenient access to a variety of functionalized tetrahydropyrans in excellent diastereoselectivities and good to excellent yields.