15561-33-8Relevant academic research and scientific papers
Taking advantage of lithium monohalocarbenoid intrinsic α-elimination in 2-MeTHF: controlled epoxide ring-openingen routeto halohydrins
Ielo, Laura,Miele, Margherita,Pillari, Veronica,Senatore, Raffaele,Mirabile, Salvatore,Gitto, Rosaria,Holzer, Wolfgang,Alcántara, Andrés R.,Pace, Vittorio
supporting information, p. 2038 - 2043 (2021/03/16)
The intrinsic degradative α-elimination of Li carbenoids somehow complicates their use in synthesis as C1-synthons. Nevertheless, we herein report how boosting such an α-elimination is a straightforward strategy for accomplishing controlled ring-opening of epoxides to furnish the corresponding β-halohydrins. Crucial for the development of the method is the use of the eco-friendly solvent 2-MeTHF, which forces the degradation of the incipient monohalolithium, due to the very limited stabilizing effect of this solvent on the chemical integrity of the carbenoid. With this approach, high yields of the targeted compounds are consistently obtained under very high regiocontrol and, despite the basic nature of the reagents, no racemization of enantiopure materials is observed.
Efficient conversion of alkenes to chlorohydrins by a Ru-based artificial enzyme
Lopez, Sarah,Rondot, Laurianne,Cavazza, Christine,Iannello, Marina,Boeri-Erba, Elisabetta,Burzlaff, Nicolai,Strinitz, Frank,Jorge-Robin, Adeline,Marchi-Delapierre, Caroline,Ménage, Stéphane
supporting information, p. 3579 - 3582 (2017/03/31)
Artificial enzymes are required to catalyse non-natural reactions. Here, a hybrid catalyst was developed by embedding a novel Ru complex in the transport protein NikA. The protein scaffold activates the bound Ru complex to produce a catalyst with high regio- and stereo-selectivity. The hybrid efficiently and stably produced α-hydroxy-β-chloro chlorohydrins from alkenes (up to 180 TON with a TOF of 1050 h?1).
Cross-Linked Artificial Enzyme Crystals as Heterogeneous Catalysts for Oxidation Reactions
Lopez, Sarah,Rondot, Laurianne,Leprêtre, Chloé,Marchi-Delapierre, Caroline,Ménage, Stéphane,Cavazza, Christine
supporting information, p. 17994 - 18002 (2017/12/26)
Designing systems that merge the advantages of heterogeneous catalysis, enzymology, and molecular catalysis represents the next major goal for sustainable chemistry. Cross-linked enzyme crystals display most of these essential assets (well-designed mesoporous support, protein selectivity, and molecular recognition of substrates). Nevertheless, a lack of reaction diversity, particularly in the field of oxidation, remains a constraint for their increased use in the field. Here, thanks to the design of cross-linked artificial nonheme iron oxygenase crystals, we filled this gap by developing biobased heterogeneous catalysts capable of oxidizing carbon-carbon double bonds. First, reductive O2 activation induces selective oxidative cleavage, revealing the indestructible character of the solid catalyst (at least 30 000 turnover numbers without any loss of activity). Second, the use of 2-electron oxidants allows selective and high-efficiency hydroxychlorination with thousands of turnover numbers. This new technology by far outperforms catalysis using the inorganic complexes alone, or even the artificial enzymes in solution. The combination of easy catalyst synthesis, the improvement of "omic" technologies, and automation of protein crystallization makes this strategy a real opportunity for the future of (bio)catalysis.
External trapping of halomethyllithium enabled by flow microreactors
Degennaro, Leonardo,Fanelli, Flavio,Giovine, Arianna,Luisi, Renzo
supporting information, p. 21 - 27 (2015/01/30)
This work demonstrates that the accurate control of the reaction parameters realized within microreactor systems allowed for a taming of the reactivity of thermally unstable intermediates such as haloalkyllithiums. The first example of effective external trapping of a reactive carbenoid such as the chloromethyllithium is described. By using microreactor systems, a continuous flow synthesis of chloro alcohols and chloro amines could be achieved with high yields. By controlling the residence time the highly reactive chloromethyllithium could be generated and reacted with electrophiles at temperatures much higher than in batch-mode and without internal quenching. The developed continuous-flow process matches the requirements for sustainability.
The vicinal functionalization of olefins: A facile route to the direct synthesis of β-chlorohydrins and β-chloroethers
Swamy, Peraka,Kumar, Macharla Arun,Reddy, Marri Mahender,Naresh, Mameda,Srujana, Kodumuri,Narender, Nama
, p. 26288 - 26294 (2014/07/08)
An efficient and environmentally benign protocol for the synthesis of vicinal chlorohydroxy and chloromethoxy derivatives in a highly regioselective manner from olefins using NH4Cl as a chlorine source and oxone as an oxidant in aqueous acetone and methanol is demonstrated. This methodology offers an additive and metal chloride free approach and is endowed with simple reaction conditions, high yields a broad substrate scope and good functional group tolerance. Moreover, the aromatic substrates with a terminal double bond exhibited merely Markovnikov selectivity, while the internal alkenes show exclusive regiocontrol and low to moderate diastereoselectivity.
Thiourea catalysis of NCS in the synthesis of chlorohydrins
Bentley, Paul A.,Mei, Yujiang,Du, Juan
, p. 1425 - 1427 (2008/09/18)
Thiourea catalysis of reactions utilizing N-succinimides is demonstrated with NCS chlorination of olefins in the presence of water to afford chlorohydrins.
Trichloroisocyanuric Acid as a Cohalogenating Reagent: An Efficient Transformation of Alkenes into Chlorohydrins, β-Chloroethers and β-Chloroacetates
Mendonca, Gabriela Fonseca,Sanseverino, Antonio Manzolillo,Mattos, Marcio C. S. de
, p. 45 - 48 (2007/10/03)
The preparation of diverse β-chloroethers, β-chloroacetates, and chlorohydrins is efficiently achieved under mild conditions by reaction of alkenes with trichloroisocyanuric acid (0.34 mol equiv) in alcohols (MeOH, EtOH, i-PrOH, t-BuOH), acetic acid or aqueous acetone, respectively.
Proprietes nucleophiles des carbenoides monohalogenes non fonctionnels
Villieras, J.,Kirschleger, B.,Tarhouni, R.,Rambaud, M.
, p. 470 - 478 (2007/10/02)
The coupling of non functionalised monohalocarbenoids R1-CXLi-R2 1 (R1 = alkyl, H ; R2 = H, CH3) with carbonyl compounds at -115 degree leads to the formation of lithium salts of halohydrins which readily give epoxides (via lithium halide elimination) at -95 degree in the presence of lithium bromide.The regiospecific synthesis of α-haloketones and α-haloaldehydes can be achieved by acylation of 1 with esters.A total lack of reactivity of 1 towards powerful alkylating electrophiles has been observed showing that they are not nucleophilic organometallics.The reactivity with carbonyl compounds seems to be promoted by the carbonyl-lithium (from the carbenoid) complexation.A correlation between nucleophilic/electrophilic properties of carbenoids (mono-, di- and trihalo-) and their assigned structure (metallocarbenium halides) is discussed.
MONOHALOMETHYLLITHIUM XCH2Li : STABILIZATION OF A POTENTIAL SYNTHETIC REAGENT
Tarhouni, R.,Kirschleger, B.,Rambaud, M.,Villieras, J.
, p. 835 - 838 (2007/10/02)
The preparation of monohalomethyllithium XCH2Li is achieved by Bromine-lithium exchange from the corresponding Bromohalomethane in the presence of one equivalent of lithium bromide at -110 degC in THF-Ether-Pentane solutions.This reagent, on coupling with various carbonyl compounds leads to halohydrins, epoxides and α-halomethyl ketones with high yields.
