73504-72-0Relevant articles and documents
Rapid, One-Step Synthesis of α-Ketoacetals via Electrophilic Etherification
Paris, Timothy J.,Schwartz, Chris,Sundall, Eric,Willand-Charnley, Rachel
supporting information, p. 14797 - 14811 (2021/10/20)
Herein, we report a rapid, one-step synthesis of α-ketoacetals via electrophilic etherification of α-alkoxy enolates and monoperoxyacetals. Methyl, primary, and secondary α-ketoacetals were obtained in 44-63% yields from tetrahydropyranyl substrates; usin
Synergistic Activation of Amides and Hydrocarbons for Direct C(sp3)–H Acylation Enabled by Metallaphotoredox Catalysis
Baik, Mu-Hyun,Choi, Seulhui,Hong, Soon Hyeok,Lee, Geun Seok,Won, Joonghee
, p. 16933 - 16942 (2020/08/03)
The utilizations of omnipresent, thermodynamically stable amides and aliphatic C(sp3)?H bonds for various functionalizations are ongoing challenges in catalysis. In particular, the direct coupling between the two functional groups has not been realized. Here, we report the synergistic activation of the two challenging bonds, the amide C?N and unactivated aliphatic C(sp3)?H, via metallaphotoredox catalysis to directly acylate aliphatic C?H bonds utilizing amides as stable and readily accessible acyl surrogates. N-acylsuccinimides served as efficient acyl reagents for the streamlined synthesis of synthetically useful ketones from simple C(sp3)?H substrates. Detailed mechanistic investigations using both computational and experimental mechanistic studies were performed to construct a detailed and complete catalytic cycle. The origin of the superior reactivity of the N-acylsuccinimides over other more reactive acyl sources such as acyl chlorides was found to be an uncommon reaction pathway which commences with C?H activation prior to oxidative addition of the acyl substrate.
Photocatalytic α-Acylation of Ethers
Sun, Zhongdong,Kumagai, Naoya,Shibasaki, Masakatsu
supporting information, p. 3727 - 3730 (2017/07/26)
Direct coupling of ethers and acyl halides was promoted by a binary catalytic system comprising an Ir-based photocatalyst and a Ni complex under blue-light irradiation. Photocatalysts with high triplet energy directed the catalysis, and the reaction likely proceeded by triplet-triplet energy transfer from the excited photocatalysts. Chlorine radicals generated from an excited Ni complex bearing a Ni-Cl bond would be responsible for generating α-oxy radicals leading to the α-acylated ethers.
Oxacycle synthesis via intramolecular reaction of carbanions and peroxides
Willand-Charnley, Rachel,Puffer, Benjamin W.,Dussault, Patrick H.
, p. 5821 - 5823 (2014/05/20)
The intramolecular reaction of dialkyl peroxides with carbanions, generated via chemoselective metal-heteroatom exchange or deprotonation, provides a new approach to cyclic ethers. Applied in tandem with C-C bond formation, the strategy enables a one-step annelation to form oxaospirocycles.
Stereochemistry of addition of organometallic reagents to 2-acyloxanes and 2-acylthianes
Alvarez-Wright, Maria Teresa,Satici, Hikmet,Eliel, Ernest L.,White, Peter S.
, p. 617 - 629 (2007/10/03)
The stereochemistry of addition of a number of organometallic reagents, including methyllithium, methyllithium-YbCl3, 1-pentynyllithium, and 1-pentynyllithium-YbCl3 to 2-acyloxanes, 2-benzoylthianes, several substituted 1,3-oxathianes and 2-methoxyacetylthiane has been studied. For the ring systems containing oxygen atoms, almost all of the additions proceed in accordance with Cram's chelate rule, on the assumption that the chelation takes place with the oxygen rather than the sulfur atoms of the ring where both are present. An exception (cf. Utimoto et al.7) is the addition of 1-pentynyllithium-YbCl3 to conformationally locked 1,3-oxathianes; however, addition of methyllithium-YbCl3 to all 1,3-oxathianes studied and of pentynyllithium-YbCl3 to the conformationally mobile 2-benzoyl-1,3-oxathiane proceeds 'normally'. Additions to 2-benzoylthiane are usually of low stereoselectivity and often proceed contrary to what would be predicted on the assumption that the organometallic reagent chelates with sulfur; an exception is methylmagnesium iodide which does follow Cram's chelate rule. The additions of RLi and RLi.YbCl3 (R methyl or 1-pentynyl) to 2-benzoylthiane follow the same stereochemical course presumably proceeding contrary to Cram's chelate rule; thus the reversal observed with 1-pentynyllithium-YbCl3 in the 1,3-oxathiane series appears not to be due to chelation with sulfur. The results with 2-methoxyacetylthiane suggest that chelation with the side-chain oxygen substituent prevails over chelation with the ring sulfur atom.
A Direct Synthesis of α-Keto Five- and Six-Membered Cyclic Ethers
Enholm, Eric J.,Schreier, Jeffrey A.
, p. 109 - 112 (2007/10/02)
A simple synthesis of tetrahydro-2H-pyran-2-yl and tetrahydrofuran-2-yl ketones from their corresponding carboxylic acids was studied.A comparison was made of organolithium and Grignard alkylating reagents as a means of reducing the formation of byproduct
