Titanocene-Catalyzed Cyclocarbonylation of Enynes to Cyclopentenones

Hicks, Frederick A.; Kablaoui, Natasha M.; Buchwald, Stephen L.

doi:10.1021/ja9621509

Cited by 148 publications

(75 citation statements)

References 19 publications

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“…(33) [82,83]. This complex is able to catalyze the Scheme 9 Formation of chiral catalysts in situ by addition of chiral phosphines Scheme 10 PKR with anchored cobalt complex catalysis reaction of different 1,6 and 1,7-enynes (31) with excellent functional group tolerance and under low CO pressure, but fails to react with sterically hindered olefins and alkynes.…”

Section: Catalytic Pkrmentioning

confidence: 99%

Cascade Reactions Involving Pauson—Khand and Related Processes

Pérez‐Castells

2006

ChemInform

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Section: Catalytic Pkrmentioning

confidence: 99%

Cascade Reactions Involving Pauson—Khand and Related Processes

Pérez‐Castells

2006

ChemInform

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“…[41][42][43] The first protocol involved the use of the complex [Cp 2 Ti(PMe 3 ) 2 ], which proved to be extremely airsensitive and failed to cyclize common enynes under 1 atm of carbon monoxide. [41] To overcome this problem, trialkylsilyl cyanides were used to generate isocyanides in situ.…”

Section: Optimization Of Titanium Catalystsmentioning

confidence: 99%

“…[43] This complex cyclized a range of enynes under low pressures of carbon monoxide (1.22 atm), thus avoiding the use of isocyanides and the unwanted hydrolysis step (Table 3, entry 2). Moreover, the TONs were substantially higher and the system displayed an increased level of functional-group compatibility.…”

Section: Optimization Of Titanium Catalystsmentioning

confidence: 99%

The Pauson–Khand Reaction: the Catalytic Age Is Here!

2003

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As a consequence of growing environmental awareness, it is now inappropriate to design a synthetic metal-mediated transformation that involves a noncatalytic use of toxic and expensive transition-metal species. One of the earliest examples of such a metal-mediated transformation is the Pauson-Khand reaction, a [2+2+1] cyclocarbonylation that generates a cyclopentenone. Despite the early descriptions by Pauson and co-workers of catalytic versions of the reaction with octacarbonyldicobalt(0), applications of the Pauson-Khand reaction have to date almost exclusively used approaches that involve stoichiometric quantities of cobalt-carbonyl complexes. In the last decade, and, most markedly, in the last two to three years, however, there have been many exciting and novel developments in the catalytic Pauson-Khand reaction. Furthermore, asymmetric catalysis of the Pauson-Khand reaction has been shown to be a viable process. In view of the impressive developments in Pauson-Khand catalysis in the last two to three years, we present a comprehensive and critical coverage of the catalytic Pauson-Khand reaction that is designed to facilitate its application and to point to exciting future developments.

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“…[18] Buchwald und Mitarbeiter veröffentlichten 1996 ein hervorragendes Verfahren zur direkten, Titanocen-katalysierten Cyclocarbonylierung von Eninen. [19] [20] entstehen die gewünschten Cyclopentenone in hoher Enantiomerenreinheit (Schema 6). …”

Section: Katalytische Variantenunclassified

“…Es wäre interessant, sie einmal an den achiralen Analoga der von Perica Á s eingesetzten Ausgangsverbindungen zu testen. [19,29] Cazes und Mitarbeiter berichteten, daû auch cobaltvermittelte interund intramolekulare Umsetzungen von Allenen mit Alkinen realisierbar sind (Schema 8).…”

Section: Asymmetrische Pauson-khand-reaktionenunclassified