carbonyl allylation

In 1978, Hoffmann reported the first asymmetric carbonyl allylation using a chiral allylmetal reagent, an allylborane derived from camphor.{{Cite journal|last1=Herold|first1=Thomas|last2=Hoffmann|first2=Reinhard W.|date=1978-10-01|title=Enantioselective Synthesis of Homoallyl Alcohols via Chiral Allylboronic Esters|journal=Angewandte Chemie International Edition in English|volume=17|issue=10|pages=768–769|doi=10.1002/anie.197807682}}{{Cite journal|last1=Hoffmann|first1=Reinhard W.|last2=Herold|first2=Thomas|date=1981-01-01|title=Stereoselektive Synthese von Alkoholen, VII1) Optisch aktive Homoallylalkohole durch Addition chiraler Boronsäureester an Aldehyde|journal=Chemische Berichte|volume=114|issue=1|pages=375–383|doi=10.1002/cber.19811140139}} Such methods utilize preformed allyl metal reagents. The approach is well developed using allyl boranesDenmark, S. E.; Almstead, N. G. In Modern Carbonyl Chemistry; Otera, J., Ed.; Wiley-VCH: Weinheim, 2000; Chapter 10.

(13)File:AlstanComp.png As illustrated by the Keck allylation, catalytic enantioselective additions of achiral allylmetal reagents to carbonyl compounds also are possible by organostannane additions.{{Cite journal|last1=Denmark|first1=Scott E.|last2=Fu|first2=Jiping|date=2003-08-01|title=Catalytic Enantioselective Addition of Allylic Organometallic Reagents to Aldehydes and Ketones|url=https://pubs.acs.org/doi/10.1021/cr020050h|journal=Chemical Reviews|language=en|volume=103|issue=8|pages=2763–2794|doi=10.1021/cr020050h|pmid=12914480|issn=0009-2665}}

Allylic boronate and -borane reagents have also been developed for enantioselective addition to carbonyls—in this class of reactions, the allylic boron reagent confers stereochemical control

(13)File:AlstanComp.png

In 1991, Yamamoto disclosed the first catalytic enantioselective method for carbonyl allylation, which employed a chiral boron Lewis acid-catalyst in combination with allyltrimethylsilane.{{Cite journal|last1=Furuta|first1=Kyoji|last2=Mouri|first2=Makoto|last3=Yamamoto|first3=Hisashi|date=1991-01-01|title=Chiral (Acyloxy)borane Catalyzed Asymmetric Allylation of Aldehydes|journal=Synlett|volume=1991|issue=8|pages=561–562|doi=10.1055/s-1991-20797}} Numerous other catalytic enantioselective methods for carbonyl allylation followed.{{Cite journal|last1=Costa|first1=Anna Luisa|last2=Piazza|first2=Maria Giulia|last3=Tagliavini|first3=Emilio|last4=Trombini|first4=Claudio|last5=Umani-Ronchi|first5=Achille|date=1993-07-01|title=Catalytic asymmetric synthesis of homoallylic alcohols|journal=Journal of the American Chemical Society|volume=115|issue=15|pages=7001–7002|doi=10.1021/ja00068a079}}{{Cite journal|last1=Keck|first1=Gary E.|last2=Tarbet|first2=Kenneth H.|last3=Geraci|first3=Leo S.|date=1993-09-01|title=Catalytic asymmetric allylation of aldehydes|journal=Journal of the American Chemical Society|volume=115|issue=18|pages=8467–8468|doi=10.1021/ja00071a074}} Catalytic variants of the Nozaki-Hiyama-Kishi reaction represent an alternative method for asymmetric carbonyl allylation, but stoichiometric metallic reductants are required.{{Cite journal|last1=Hargaden|first1=Gráinne C.|last2=Guiry|first2=Patrick J.|date=2007-11-05|title=The Development of the Asymmetric Nozaki–Hiyama–Kishi Reaction|journal=Advanced Synthesis & Catalysis|volume=349|issue=16|pages=2407–2424|doi=10.1002/adsc.200700324}}

Whereas the aforementioned asymmetric carbonyl allylations rely on preformed allylmetal reagents, the Krische allylation exploits allyl acetate for enantioselective carbonyl allylation.{{Cite journal|last1=Kim|first1=In Su|last2=Ngai|first2=Ming-Yu|last3=Krische|first3=Michael J.|date=2008-11-05|title=Enantioselective Iridium-Catalyzed Carbonyl Allylation from the Alcohol or Aldehyde Oxidation Level via Transfer Hydrogenative Coupling of Allyl Acetate: Departure from Chirally Modified Allyl Metal Reagents in Carbonyl Addition|journal=Journal of the American Chemical Society|language=en|volume=130|issue=44|pages=14891–14899|doi=10.1021/ja805722e|issn=0002-7863|pmc=2890235|pmid=18841896}} Selected methods for asymmetric carbonyl allylation are summarized below.

File:Carbonyl Allylation Scheme 2.png

Carbonyl allylation has been employed in the synthesis of polyketide natural products and other oxygenated molecules with a contiguous array of stereocenters. For example, allylstannanation of a threose-derived aldehyde affords the macrolide antascomicin B, which structurally resembles FK506 and rapamycin, and is a potent binder of FKBP12.{{Cite journal|last1=Brittain|first1=Dominic E. A.|last2=Griffiths-Jones|first2=Charlotte M.|last3=Linder|first3=Michael R.|last4=Smith|first4=Martin D.|last5=McCusker|first5=Catherine|last6=Barlow|first6=Jaqueline S.|last7=Akiyama|first7=Ryo|last8=Yasuda|first8=Kosuke|last9=Ley|first9=Steven V.|date=2005|title=Total Synthesis of Antascomicin B|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.200500174|journal=Angewandte Chemie International Edition|volume=44|issue=18|pages=2732–2737|doi=10.1002/anie.200500174|pmid=15806607|issn=1521-3773}} The Krische allylation was used to prepare the polyketide (+)-SCH 351448, a macrodiolide ionophore bearing 14 stereogenic centers.{{Cite journal|last1=Wang|first1=Gang|last2=Krische|first2=Michael J.|date=2016-07-06|title=Total Synthesis of (+)-SCH 351448: Efficiency via Chemoselectivity and Redox-Economy Powered by Metal Catalysis|url=https://doi.org/10.1021/jacs.6b04917|journal=Journal of the American Chemical Society|volume=138|issue=26|pages=8088–8091|doi=10.1021/jacs.6b04917|issn=0002-7863|pmc=4935581|pmid=27337561}}

File:Carbonyl Allylation Scheme 3.png

==Older primary literature==

• {{Cite journal|last1=Brown|first1=Herbert C.|last2=Jadhav|first2=Prabhakar K.|date=April 1983|title=Asymmetric carbon-carbon bond formation via .beta.-allyldiisopinocampheylborane. Simple synthesis of secondary homoallylic alcohols with excellent enantiomeric purities|url=https://pubs.acs.org/doi/abs/10.1021/ja00345a085|journal=Journal of the American Chemical Society|language=en|volume=105|issue=7|pages=2092–2093|doi=10.1021/ja00345a085|issn=0002-7863}}
• {{Cite journal|last1=Hayashi|first1=Tamio|last2=Konishi|first2=Mitsuo|last3=Kumada|first3=Makoto|date=1982-09-01|title=Optically active allylsilanes. 2. High stereoselectivity in asymmetric reaction with aldehydes producing homoallylic alcohols|journal=Journal of the American Chemical Society|volume=104|issue=18|pages=4963–4965|doi=10.1021/ja00382a046}}
• {{Cite journal|last1=Roush|first1=William R.|last2=Walts|first2=Alan E.|last3=Hoong|first3=Lee K.|date=1985-12-01|title=Diastereo- and enantioselective aldehyde addition reactions of 2-allyl-1,3,2-dioxaborolane-4,5-dicarboxylic esters, a useful class of tartrate ester modified allylboronates|journal=Journal of the American Chemical Society|volume=107|issue=26|pages=8186–8190|doi=10.1021/ja00312a062}}
• {{Cite journal|last1=Brown|first1=Herbert C.|last2=Jadhav|first2=Prabhakar K.|date=April 1983|title=Asymmetric carbon-carbon bond formation via .beta.-allyldiisopinocampheylborane. Simple synthesis of secondary homoallylic alcohols with excellent enantiomeric purities|url=https://pubs.acs.org/doi/abs/10.1021/ja00345a085|journal=Journal of the American Chemical Society|language=en|volume=105|issue=7|pages=2092–2093|doi=10.1021/ja00345a085|issn=0002-7863}}
• {{Cite journal|last1=Kinnaird|first1=James W. A.|last2=Ng|first2=Pui Yee|last3=Kubota|first3=Katsumi|last4=Wang|first4=Xiaolun|last5=Leighton|first5=James L.|date=2002-07-01|title=Strained Silacycles in Organic Synthesis: A New Reagent for the Enantioselective Allylation of Aldehydes|url=https://pubs.acs.org/doi/10.1021/ja0264908|journal=Journal of the American Chemical Society|language=en|volume=124|issue=27|pages=7920–7921|doi=10.1021/ja0264908|pmid=12095334|issn=0002-7863}}
• {{Cite journal|last1=Short|first1=Robert P.|last2=Masamune|first2=Satoru|date=March 1989|title=Asymmetric allylboration with B-allyl-2-(trimethylsilyl)borolane|url=https://pubs.acs.org/doi/abs/10.1021/ja00187a061|journal=Journal of the American Chemical Society|language=en|volume=111|issue=5|pages=1892–1894|doi=10.1021/ja00187a061|issn=0002-7863}}
• {{Cite journal|last1=Corey|first1=E. J.|last2=Yu|first2=Chan Mo|last3=Kim|first3=Sung Soo|date=July 1989|title=A practical and efficient method for enantioselective allylation of aldehydes|url=https://pubs.acs.org/doi/abs/10.1021/ja00196a082|journal=Journal of the American Chemical Society|language=en|volume=111|issue=14|pages=5495–5496|doi=10.1021/ja00196a082|issn=0002-7863}}

{{organometallics}}

Category:Organometallic chemistry

Category:Carbon-carbon bond forming reactions