Addition of Organochromium Reagents to Carbonyl Compounds

Takai, Kazuhiko

doi:10.1002/0471264180.or064.03

Cited by 41 publications

(24 citation statements)

References 650 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An example is represented by the allylation under Nozaki–Hiyama–Kishi/Fürstner conditions, which combines catalytic amounts of CrCl 2 (or CrCl 3 ) and superstoichiometric amounts of Mn. [201] Although catalytic in the metal that carries out the allylation reaction itself, protocols of this kind are de facto not catalytic, because a stoichiometric amount of metal reducing agent is still required. Truly catalytic methods include the transfer hydrogenation approach described by Krische.…”

Section: The Water-gas Shift Reaction In Organic Synthesismentioning

confidence: 99%

Harnessing the Power of the Water‐Gas Shift Reaction for Organic Synthesis

Ambrosi

Denmark

2016

Angew Chem Int Ed

View full text Add to dashboard Cite

Since its original discovery over a century ago, the water-gas shift reaction (WGSR) has played a crucial role in industrial chemistry, providing a source of H2 to feed fundamental industrial transformations such as the Haber–Bosch synthesis of ammonia. Although the production of hydrogen remains nowadays the major application of the WGSR, the advent of homogeneous catalysis in the 1970s marked the beginning of a synergy between WGSR and organic chemistry. Thus, the reducing power provided by the CO/H2O couple has been exploited in the synthesis of fine chemicals; not only hydrogenation-type reactions, but also catalytic processes that require a reductive step for the turnover of the catalytic cycle. Despite the potential and unique features of the WGSR, its applications in organic synthesis remain largely underdeveloped. The topic will be critically reviewed herein, with the expectation that an increased awareness may stimulate new, creative work in the area.

show abstract

Section: The Water-gas Shift Reaction In Organic Synthesismentioning

confidence: 99%

Harnessing the Power of the Water‐Gas Shift Reaction for Organic Synthesis

Ambrosi

Denmark

2016

Angew Chem Int Ed

View full text Add to dashboard Cite

show abstract

“…310 A marked advantage of this carbonyl olefination over the McMurry coupling is that the chromium reagents show high chemoselectivity toward aldehydes, and can be carried out in the presence of keto and ester functionalities.…”

Section: Scheme 27mentioning

confidence: 99%

The McMurry Coupling and Related Reactions

Takeda

Tsubouchi

2013

Organic Reactions

View full text Add to dashboard Cite

The McMurry coupling reaction has been recognized as one of the most efficient methods for the synthesis of alkenes from carbonyl compounds. This reaction can be applied to the preparation of various alkenes that are otherwise difficult to prepare. For example, sterically congested tetrasubstituted alkenes as well as medium to large membered rings involving natural products may be accessed via this process. This coupling utilizes various low‐valent titanium reagents generated by the reduction of titanium (III or IV) chloride with K, Zn, LiAlH 4 , C 8 K, amongst others. Furthermore, a variety of low‐valent metal species other than titanium, including aluminum, zirconium, niobium, molybdenum, indium, tungsten, and samarium, have also been found to promote the reductive coupling of carbonyl compounds. The scope and limitations of these reagent systems are reviewed in this chapter, together with the stereochemistry and reaction mechanism. This reaction is categorized into four coupling modes: i) homocoupling giving symmetrical alkenes, ii) mixed coupling giving unsymmetrical alkenes, iii) intramolecular coupling giving cycloalkenes, and iv) tandem coupling giving cyclic polyenes. Characteristics of these reaction modes are described briefly. A selection of synthetic applications are reviewed, including examples of the preparation of sterically congested and strained alkenes, medium to large‐ring compounds, biologically active targets, as well as substrates applicable in material science. Experimental conditions used for this versatile process are summarized to assist the choice of suitable conditions.

show abstract

“…To tell the truth, I did not think at that time that the result of the reaction would initiate a new field of organochromium reagents and result in a review in Organic Reactions. 13 Further experiments revealed that reduction of alkenyl and aryl iodides (or bromides) to alkenyl-and arylchromium reagents with chromium(II) chloride and subsequent Barbiertype carbonyl addition proceeded smoothly. The reaction occurred in a stereoselective manner.…”

mentioning

confidence: 99%

“…13,32,34 1.3 Geminal Dimetallic Reagents for Olefination of Carbonyl Groups: Organotitanium Reagents.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Trace Amounts of Second Metal Elements Can Play a Key Role in the Generation of Organometallic Compounds

Takai

2015

Bulletin of the Chemical Society of Japan

Self Cite

View full text Add to dashboard Cite

). He has developed several synthetic methods using early transition metals such as chromium, titanium, and tantalum. Current research in his group is aimed towards the use of the complexes of group 7 metals as catalysts in organic synthesis and C-H activation initiated by insertion of transition metals into heteroatom-hydrogen bonds. AbstractDuring the development of new synthetic organic reactions by the use of group 47 metals, we twice encountered a reproducibility problem. The key factor was trace amounts of second metal elements that contaminated the first, main metals, i.e., nickel in chromium and lead in zinc. We had determined the standard procedures for these reactions and they were adopted in Organic Syntheses. The difference in the source of zinc, i.e., contamination by a catalytic amount of lead, proved to affect both the reactivity of the SimmonsSmith reaction and the formation of alkylzinc from the corresponding iodides. By using the concept of catalytic effects of the second metals, we developed a method to use manganese metal and applied this to sequential radical and anionic reactions. In addition, allylic aluminum species were prepared smoothly from allylic halides and aluminum by addition of an indium salt, the second element. In this account, I describe how the synthetic methods were discovered and developed, with an emphasis on the stories behind the communications and articles.

show abstract

Addition of Organochromium Reagents to Carbonyl Compounds

Cited by 41 publications

References 650 publications

Harnessing the Power of the Water‐Gas Shift Reaction for Organic Synthesis

Harnessing the Power of the Water‐Gas Shift Reaction for Organic Synthesis

The McMurry Coupling and Related Reactions

Trace Amounts of Second Metal Elements Can Play a Key Role in the Generation of Organometallic Compounds

Contact Info

Product

Resources

About