- Rhodium-Catalyzed Deoxygenation and Borylation of Ketones: A Combined Experimental and Theoretical Investigation
-
The rhodium-catalyzed deoxygenation and borylation of ketones with B2pin2 have been developed, leading to efficient formation of alkenes, vinylboronates, and vinyldiboronates. These reactions feature mild reaction conditions, a broad substrate scope, and excellent functional-group compatibility. Mechanistic studies support that the ketones initially undergo a Rh-catalyzed deoxygenation to give alkenes via boron enolate intermediates, and the subsequent Rh-catalyzed dehydrogenative borylation of alkenes leads to the formation of vinylboronates and diboration products, which is also supported by density functional theory calculations.
- Tao, Lei,Guo, Xueying,Li, Jie,Li, Ruoling,Lin, Zhenyang,Zhao, Wanxiang
-
supporting information
p. 18118 - 18127
(2020/11/26)
-
- I-Pr2NMgCl·LiCl Enables the Synthesis of Ketones by Direct Addition of Grignard Reagents to Carboxylate Anions
-
The direct preparation of ketones from carboxylate anions is greatly limited by the required use of organolithium reagents or activated acyl sources that need to be independently prepared. Herein, a specific magnesium amide additive is used to activate and control the addition of more tolerant Grignard reagents to carboxylate anions. This strategy enables the modular synthesis of ketones from CO2 and the preparation of isotopically labeled pharmaceutical building blocks in a single operation.
- Colas, Kilian,Dos Santos, A. Catarina V. D.,Mendoza, Abraham
-
supporting information
(2019/10/08)
-
- Suzuki-Miyaura coupling of simple ketones via activation of unstrained carbon-carbon bonds
-
Here, we describe that simple ketones can be efficiently employed as electrophiles in Suzuki-Miyaura coupling reactions via catalytic activation of unstrained C-C bonds. A range of common ketones, such as cyclopentanones, acetophenones, acetone and 1-indanones, could be directly coupled with various arylboronates in high site-selectivity, which offers a distinct entry to more functionalized aromatic ketones. Preliminary mechanistic study suggests that the ketone α-C-C bond was cleaved via oxidative addition.
- Xia, Ying,Wang, Jianchun,Dong, Guangbin
-
supporting information
p. 5347 - 5351
(2018/05/03)
-
- A Fluorinated Ligand Enables Room-Temperature and Regioselective Pd-Catalyzed Fluorination of Aryl Triflates and Bromides
-
A new biaryl monophosphine ligand (AlPhos, L1) allows for the room-temperature Pd-catalyzed fluorination of a variety of activated (hetero)aryl triflates. Furthermore, aryl triflates and bromides that are prone to give mixtures of regioisomeric aryl fluorides with Pd-catalysis can now be converted to the desired aryl fluorides with high regioselectivity. Analysis of the solid-state structures of several Pd(II) complexes, as well as density functional theory (DFT) calculations, shed light on the origin of the enhanced reactivity observed with L1.
- Sather, Aaron C.,Lee, Hong Geun,De La Rosa, Valentina Y.,Yang, Yang,Müller, Peter,Buchwald, Stephen L.
-
supporting information
p. 13433 - 13438
(2015/11/09)
-
- Highly chemoselective and versatile method for direct conversion of carboxylic acids to ketones utilizing zinc Ate complexes
-
Various carboxylic acids were directly transformed into the corresponding ketones by utilizing organozinc ate complexes, which provide high chemoselectivity without any overreaction to the undesired tertiary carbinol, owing to formation of a stable tetrahedral zincioketal intermediate. This method offers good overall atom/step/pot economy and operational simplicity. No need to overreact: Various carboxylic acids were directly transformed to the corresponding ketones by utilizing organozinc ate complexes, which provide high chemoselectivity without any overreaction to undesired tertiary carbinol, owing to formation of a stable tetrahedral zincioketal intermediate. This method offers good overall atom/step/pot economy and operational simplicity.
- Murata, Ryo,Hirano, Keiichi,Uchiyama, Masanobu
-
supporting information
p. 1286 - 1290
(2015/06/08)
-
- Continuous flow synthesis of ketones from carbon dioxide and organolithium or grignard reagents
-
We describe an efficient continuous flow synthesis of ketones from CO 2 and organolithium or Grignard reagents that exhibits significant advantages over conventional batch conditions in suppressing undesired symmetric ketone and tertiary alcohol byproducts. We observed an unprecedented solvent-dependence of the organolithium reactivity, the key factor in governing selectivity during the flow process. A facile, telescoped three-step-one-flow process for the preparation of ketones in a modular fashion through the in-line generation of organometallic reagents is also established.
- Wu, Jie,Yang, Xiaoqing,He, Zhi,Mao, Xianwen,Hatton, T. Alan,Jamison, Timothy F.
-
supporting information
p. 8416 - 8420
(2014/08/18)
-
- Mild and direct conversion of esters to morpholine amides using diisobutyl(morpholino)aluminum: Application to efficient one-pot synthesis of ketones and aldehydes from esters
-
Morpholine amide intermediates, which are easily prepared by aminolysis of various esters with diisobutyl(morpholino)aluminum, react with organolithium and reducing agents (DIBALH or LDBMA) without isolation of the aminolysis intermediates to give ketones in 83-95% yields and aldehydes quantitatively.
- Jeon, Ah Ram,Kim, Min Eai,Park, Jae Kyo,Shin, Won Kyu,An, Duk Keun
-
p. 4420 - 4424
(2014/06/10)
-
- Pd-catalyzed nucleophilic fluorination of aryl bromides
-
On the basis of mechanism-driven reaction design, a Pd-catalyzed nucleophilic fluorination of aryl bromides and iodides has been developed. The method exhibits a broad substrate scope, especially with respect to nitrogen-containing heteroaryl bromides, and proceeds with minimal formation of the corresponding reduction products. A facilitated ligand modification process was shown to be critical to the success of the reaction.
- Lee, Hong Geun,Milner, Phillip J.,Buchwald, Stephen L.
-
supporting information
p. 3792 - 3795
(2014/04/03)
-
- An effective one-pot conversion of acid chlorides to aldehydes and ketones
-
Aldehydes and ketones were synthesized from their respective acid chlorides via a one-pot protocol. Morpholine amide intermediates that were readily prepared by the aminolysis of various acid chlorides with diisobutyl(morpholino) aluminum smoothly reacted with the reducing agent LDBMA and the organolithium reagents under mild reaction conditions (0 C), giving almost excellent product yields of up to 95%.
- Park, Jae Kyo,Shin, Won Kyu,An, Duk Keun
-
p. 3199 - 3203
(2013/06/27)
-
- Cyanocuprates convert carboxylic acids directly into ketones
-
Carboxylic acids were converted directly in 56-99% yields into methyl, n-butyl, and isopropyl ketones using excess cyanocuprates R2CuLi 3 LiCN. A substrate with a stereocenter α to the carboxylic acid was converted into ketones with very little loss of enantiomeric purity. A variety of functional groups were tolerated including aryl bromides. This direct transformation of a carboxylic acid into ketone with minimal tertiary alcohol formation is proposed to involve a relatively stable copper ketal tetrahedral intermediate.
- Genna, Douglas T.,Posner, Gary H.
-
supporting information; experimental part
p. 5358 - 5361
(2011/12/15)
-
- Direct conversion of N-methoxy-N-methylamides (Weinreb amides) to ketones via a nonclassical Wittig reaction
-
(Chemical Equation Presented) N-Methoxy-N-methylamides (Weinreb amides) are converted efficiently into ketones by reaction with alkylidenetriphenylphosphoranes and in situ hydrolysis of the product.
- Murphy, John A.,Commeureuc, Aurelien G. J.,Snaddon, Thomas N.,McGuire, Thomas M.,Khan, Tanweer A.,Hisler, Kevin,Dewis, Mark L.,Carling, Robert
-
p. 1427 - 1429
(2007/10/03)
-
- New Method for Generation of β-Oxido Carbenoid via Ligand Exchange Reaction of Sulfoxides: A Versatile Procedure for One-Carbon Homologation of Carbonyl Compounds
-
A new procedure for one-carbon homologation of carbonyl compounds is described.The method is based on the rearrangement of β-oxido carbenoid which is generated via the ligand exchange reaction of the sulfinyl group of α-chloro β-hydroxy sulfoxide with tert-butyllithium.Addition of the carbanion of aryl 1-chloroalkyl sulfoxides to carbonyl compounds gave the adducts in good yields.The β-oxido carbenoid rearrangement of the adducts gave one-carbon homologated carbonyl compounds having an α-alkyl substituent.A similar reaction of the adducts derived from carbonyl compounds with chloromethyl p-tolyl sulfoxide yielded a procedure for a methylene insertion.The stereochemistry of the β-oxido carbenoid rearrangenment is also discussed.
- Satoh, Tsuyoshi,Itoh, Norifumi,Gengyo, Kaoru,Takada, Sae,Asakawa, Naoyuki,et al.
-
p. 11839 - 11852
(2007/10/02)
-
- Deactivation of Triplet Phenyl Alkyl Ketones by Conjugatively Electron-Withdrawing Substituents
-
Para-cyano, -carbomethoxy, and -acyl substituents decrease the triplet reactivity of valerophenone (γ-hydrogen abstraction), whereas comparable meta substituents increase reactivity.Spectroscopic results are presented which indicate that para-(-R) substituents lower ?,?* triplet energies so much more than n,?* energies that the lowest triplets become largely ?,?* in nature.Meta-(-R) substituents do not stabilize ?,?* triplets enough to invert triplet levels.Both substitution patterns support a largely 1,4-biradical structure for the lowest ?,?* triplet of acylbenzenes.Ortho substituents show the usual steric anomalies: ortho cyano enhances valerophenone triplet reactivity by stabilizing the n,?* triplet; ortho carbomethoxy deactivates valerophenone by stabilizing the ?,?* triplet but not the n,?.*
- Wagner, Peter J.,Siebert, Elizabeth J.
-
p. 7329 - 7335
(2007/10/02)
-
