Directed chiral synthesis with pinanediol boronic esters

Matteson, Donald S.; Ray, Rahul

doi:10.1021/ja00545a046

Cited by 163 publications

(78 citation statements)

References 4 publications

(6 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Unfortunately, while this process had worked well for tertiary pinacol boronic esters, [5a] it worked poorly for secondary pinacol boronic esters, giving mixtures of the starting material, the desired product, and overhomologated products. [8] We then designed a two-step, onepot protocol that consists of 1) a Matteson homologation [9] with dichloromethyl lithium to give 9, followed by 2) the in situ treatment with vinyl magnesium bromide (Scheme 2). This procedure routinely gave boronic ester 8 in high yield and could be easily carried out on multi-gram scale.…”

Section: IImentioning

confidence: 99%

Stereocontrolled Synthesis of 1,5‐Stereogenic Centers through Three‐Carbon Homologation of Boronic Esters

2014

View full text Add to dashboard Cite

Allylic pinacol boronic esters are stable toward 1,3-borotropic rearrangement. We developed a Pd II -mediated isomerization process that gives di-or trisubstituted allylic boronic esters with high E selectivity. The combination of this method with lithiation-borylation enables the synthesis of carbon chains that bear 1,5-stereogenic centers. The utility of this method has been demonstrated in a formal synthesis of (+)-jasplakinolide.Polyketide natural products are replete with carbon chains that bear 1,5-stereogenic centers connected by alkyl, di-or trisubstituted alkenyl groups (Figure 1).[1] Numerous ingenious strategies have been devised for the synthesis of these natural products, but control of the double-bond geometry, especially in the case of tri-substituted alkenyl groups, can sometimes be challenging. [2] Recently, lithiation-borylation has emerged as a powerful tool to control the stereochemistry along a carbon chain and to build up multiple stereogenic centers with high stereocontrol. [3] In order to use lithiation-borylation to create compound arrays that bear 1,5-stereogenic centers, a threecarbon homologation of boronic ester 1 to an allylic boronic ester intermediate 2 would be required, which would then be set up for further homologations (Scheme 1 a). While there was one report of a three-carbon homologation of a boronic ester, this homologation required the use of unstable and difficult-to-handle propylene glycol boronic esters 3 (Scheme 1 a).[4] Furthermore, these substrates perform poorly in lithiation-borylation processes, thus limiting their use in asymmetric synthesis. In contrast, pinacol boronic esters perform well in lithiation-borylation processes, and so we needed to find conditions under which such esters could be employed in three-carbon homologations.In order to achieve our goal, we needed to 1) carry out a homologation to give allylic boronic ester 4 followed by 2) a diastereoselective 1,3-borotropic shift to give boronic ester 5 (Scheme 1 c). Both steps presented challenges. First of all, we needed to establish a general and efficient protocol for the homologation of a broad range of pinacol boronic esters to allylic boronic esters 4.[5] Secondly, conditions for the key 1,3-borotropic shift needed to be identified to maximize the reaction efficiency and more importantly to control the olefin geometry. It is important to note that while less sterically hindered allylic boronic esters (and boranes) [6] are known to undergo a 1,3-borotropic shift upon heating, pinacol allylic boronic esters have been shown to be thermally stable. [7] Despite the limited precedence, we initiated a research program aimed at addressing this challenge, anticipating that its solution would be highly useful for the synthesis of many relevant molecules. Herein we describe the first threecarbon homologation of pinacol boronic esters, introducing a di-or tri-substituted alkenyl unit with high stereocontrol over the double-bond geometry. This methodology was

show abstract

Section: IImentioning

confidence: 99%

Stereocontrolled Synthesis of 1,5‐Stereogenic Centers through Three‐Carbon Homologation of Boronic Esters

2014

View full text Add to dashboard Cite

show abstract

“…Another coupling of 3a-3m with L-P 3 CH 2 (HClÁNH 2 )COOCH 3 and saponification was repeated to gain the important dipeptides 5a-5m in high yield. The known amine boronate 8 was synthesized according to Matteson's procedure [14][15][16][17] and coupled with dipeptides 5a-5m in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) 18 to provide pure boronates 6a-6m (listed in Table 1) in high yield (78-87%) after chromatographic purification. And then the protecting group pinanediol was removed by BBr 3 under mild conditions to give the target tripeptide boronic acids 7a-7m (listed in Table 1).…”

Section: Synthesis Of Boronic Acidsmentioning

confidence: 99%

Design, synthesis and biological evaluation of tripeptide boronic acid proteasome inhibitors

Zhu

Yao

et al. 2009

Bioorganic & Medicinal Chemistry

View full text Add to dashboard Cite

“…2). Matteson et al developed a stereoselective homologation of pinanediol boronic esters with (dichloromethyl)lithium to chiral a-chloro boronic esters 51) and expanded this reaction to the synthesis of (R)-lacetamido-2-phenylethanebofonic acid (30), a boronic acid analogue of N-acetyl-L-phenylalanine. 52 ) Compound 30 competitively inhibited chymotrypsin with an inhibition constant of 2.1 fJM.…”

Section: Serine Protease Inhibitorsmentioning

confidence: 99%

Aminophosphonic and Aminoboronic Acids as Key Elements of a Transition State Analogue Inhibitor of Enzymes

Hiratake

Oda

1997

Bioscience, Biotechnology, and Biochemistry

164

View full text Add to dashboard Cite

Directed chiral synthesis with pinanediol boronic esters

Cited by 163 publications

References 4 publications

Stereocontrolled Synthesis of 1,5‐Stereogenic Centers through Three‐Carbon Homologation of Boronic Esters

Stereocontrolled Synthesis of 1,5‐Stereogenic Centers through Three‐Carbon Homologation of Boronic Esters

Design, synthesis and biological evaluation of tripeptide boronic acid proteasome inhibitors

Aminophosphonic and Aminoboronic Acids as Key Elements of a Transition State Analogue Inhibitor of Enzymes

Contact Info

Product

Resources

About