Chemo‐ and Regioselective Palladium‐Catalyzed Oxycyclization Reactions of Allendiols: Preparation of Five‐, Six‐, and Eight‐Membered Cycles

Alcaide, Benito; Almendros, Pedro; Carrascosa, Rocío; Campo, Teresa Martínez del

doi:10.1002/chem.200802675

Cited by 39 publications

(12 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The asymmetric bromoetherification of 4 a could also be achieved to afford product 7 a in 64 % yield and 90 % ee with a Pd/Cu‐bimetallic catalytic system in the presence of lithium bromide. The ee value of 7 a was determined after debromination (Scheme ) 11. The absolute configuration of 3 was unequivocally determined by a single‐crystal X‐ray structural analysis of 7 a (Figure 1, also see the Supporting Information).…”

Section: Methodsmentioning

confidence: 99%

OP16.11: Discrepancy of first trimester crown‐rump lengths and birth weights in twins of Chinese population

Chou

Cheong

Lee

et al. 2008

Ultrasound in Obstet & Gyne

View full text Add to dashboard Cite

A reference chart for longitudinal EWD based on ultrasound EFW is provided. Conclusions: The inter-individual variability of EWD in twins increases from 26 weeks' onward. This challenges previously published results from cross-sectional studies. Gestational-age specific cutoff values of EWD should therefore be considered. OP16.10 Effect of chorionicity, zygosity and gender on twin birth weight, weight discordance and perinatal outcome

show abstract

Section: Methodsmentioning

confidence: 99%

OP16.11: Discrepancy of first trimester crown‐rump lengths and birth weights in twins of Chinese population

Chou

Cheong

Lee

et al. 2008

Ultrasound in Obstet & Gyne

View full text Add to dashboard Cite

show abstract

“…Alcaide et al have demonstrated that b,g-and g,d-allendiols 210 undergo intramolecular cyclization to a variety of enantiopure oxacycles 211 or 212 of different ring sizes in the presence of LiBr (Scheme 58). [157] However, there are only a few examples of the catalytic enantioselective cyclic allylation by carbopalladation. In 1991,…”

Section: Cyclizations In the Presence Of Organic Halides Or Hxmentioning

confidence: 99%

Allenes in Catalytic Asymmetric Synthesis and Natural Product Syntheses

2012

Angew Chem Int Ed

963

259

View full text Add to dashboard Cite

Allenes are the simplest class of cumulenes, with two contiguous C=C bonds, and show unique physical and chemical properties. These features make allenes particularly attractive in modern organic chemistry. In this Review, attention is paid to the advances made in catalytic asymmetric synthesis and natural product syntheses based on well-established reactions of allenes, such as propargylation, addition, cycloaddition, cycloisomerization, cyclization, etc., with or without catalysts. Their versatile reactivity, substituent-loading ability, axial to center chirality transfer, and controllable selectivity allow access to target molecules by unique and efficient approaches. The main topics in this Review are presented with selected examples from 2003 to 2011.

show abstract

“…Interestingly, trans ‐fused β‐lactam oxocines 92 were obtained in good yields in a totally chemo‐ and regioselective fashion using the PdCl 2 ‐catalyzed cyclizative coupling reaction with allyl halides ( Scheme ), through an 8‐ endo ‐ trig cyclization by attack of the primary hydroxy group to the terminal allene carbon atom. [43] Apparently, this is the first example of an 8‐ endo cyclization at the terminal allene carbon atom of a δ‐allenol. Chemical evidence of the presence of a new eight‐membered oxacycle fused to the β‐lactam ring was obtained by oxidation of adduct 92a (R 1 = 4‐MeOC 6 H 4 , R 2 = Me) with DessMartin periodinane to afford ketone 93 (Scheme ).…”

Section: Heterocyclizationsmentioning

confidence: 99%

Allenyl‐β‐lactams: versatile scaffolds for the synthesis of heterocycles

Alcaide

Almendros

2011

The Chemical Record

Self Cite

View full text Add to dashboard Cite

The hybrid allenic β-lactam moiety represents an excellent building block for carbo- and heterocyclization reactions, affording a large number of cyclic structures containing different sized skeletons in a single step. This strategy has been studied under thermal and radical-induced conditions. More recently, the use of transition-metal catalysis has been introduced as an alternative that relies on the activation of the allenic component. On the other hand, the intramolecular version has attracted much attention as a strategy for the synthesis of bi- and tricyclic compounds in a regio- and stereoselective manner. This overview focuses on the most recently developed cyclizations on 2-azetidinone-tethered allenes along with remarkable early works accounting for the mechanism, as well as for the regio- and diastereoselectivities of the cyclizations.

show abstract

Chemo‐ and Regioselective Palladium‐Catalyzed Oxycyclization Reactions of Allendiols: Preparation of Five‐, Six‐, and Eight‐Membered Cycles

Cited by 39 publications

References 42 publications

OP16.11: Discrepancy of first trimester crown‐rump lengths and birth weights in twins of Chinese population

OP16.11: Discrepancy of first trimester crown‐rump lengths and birth weights in twins of Chinese population

Allenes in Catalytic Asymmetric Synthesis and Natural Product Syntheses

Allenyl‐β‐lactams: versatile scaffolds for the synthesis of heterocycles

Contact Info

Product

Resources

About