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Water microwave-superheated

Similarly, Vasudevan and Verzal have found that terminal alkynes can be hydrated under neutral, metal-free conditions using water as solvent (Scheme 4.15) [41], While this reaction typically requires a catalyst such as gold(III) bromide, employing microwave-superheated distilled water allowed this chemistry to proceed without any catalyst. Extension of this methodology led to a one-pot conversion of alkynes to imines (hydroamination). [Pg.68]

Coelho E, Rocha MA, Saraiva JA, Coimbra MA. Microwave superheated water and dilute alkali extraction of brewers spent grain arabinoxylans and arabinoxylo-oligosaccharides. Carbokydr Polym 2014 99 415-22. [Pg.672]

Pt-catalyzed hydration of various aliphatic and aromatic alkynes under phase transfer conditions in (CH2C1)2/H20 in the presence of Aliquat 336 led to either a Markovnikov product, mixtures of two ketones, or ketones with the carbonyl group positioned away from the bulky side.72 In the absence of the phase transfer reagent, Aliquat 336, hardly any reaction took place. Recently, a hydrophobic, low-loading and alkylated polystyrene-supported sulfonic acid (LL-ALPS-SO3H) has also been developed for the hydration of terminal alkynes in pure water, leading to ketones as the product.73 Under microwave irradiation, the hydration of terminal arylalkynes was reported to proceed in superheated water (200°C) without any catalysts.74... [Pg.119]

The Baran group has reported an unusual deprotection of allyl esters in micro-wave-superheated water. A diallyl ester structurally related to the sceptrin natural products (see Scheme 6.87) was cleanly deprotected at 200 °C within 5 min (Scheme 6.168) [181]. Other standard deprotection transformations carried out under microwave conditions, specifically N-detosylations [317], trimethylsilyl (TMS) removal [318, 319], and N-tert-butoxycarbonyl (Boc) deprotection [231], are summarized in Scheme 6.169. [Pg.217]

The reduction in the numbers of incinerators and the limitations of autoclaves have created the need for alternative medical waste treatment systems. Currently, there are over 40 such technologies available from greater than 70 manufacturers within the United States, Europe, the Middle East, and Australia. While these systems vary in their treatment capacity, the extent of automation, and overall volume reduction, all alternative technologies utilize one or more of the following methods (1) heating the waste to a minimum of 90 to 95°C by means of microwaves, radio waves, hot oil, hot water, steam, or superheated gases (2) exposing the waste to chemicals such as sodium hypochlorite (household bleach) or... [Pg.159]

At normal atmospheric pressure, the boiling point of water equals 100°C. Consequently, in order to obtain an internal overpressure, the temperature of the porous medium must be above that level during at least one part of the process. This is the aim of convective drying at high temperature (moist air or superheated steam) and a possible aim of contact drying or drying with an electromagnetic field (microwave or radio frequency). [Pg.815]

Superheated (subcritical) water as solvent in microwave-assisted organic synthesis of compounds of valuable pharmaceutical interest 13COC 1158. [Pg.257]

You can use your microwave to boil, but be extremely cautious of "superheating." This occurs when water heats past the boiiing point without forming bubbies to reiease air, then erupts in a dangerous, scalding voicano. Here are some tips for safer microwaving ... [Pg.8]


See other pages where Water microwave-superheated is mentioned: [Pg.108]    [Pg.672]    [Pg.344]    [Pg.801]    [Pg.63]    [Pg.152]    [Pg.128]    [Pg.146]    [Pg.133]    [Pg.249]    [Pg.515]    [Pg.430]    [Pg.406]    [Pg.412]    [Pg.33]    [Pg.75]    [Pg.8]    [Pg.6]    [Pg.308]    [Pg.229]    [Pg.57]    [Pg.845]   
See also in sourсe #XX -- [ Pg.217 ]




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