138964-33-7Relevant articles and documents
MYOGLOBIN-BASED CATALYSTS FOR CARBENE TRANSFER REACTIONS
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Paragraph 0090; 00367, (2016/06/14)
Methods are provided for carrying out carbene transfer transformations such as olefin cyclopropanation reactions, carbene heteroatom-H insertion reactions (heteroatom = N, S, Si), sigmatropic rearrangement reactions, and aldehyde olefination reactions with high efficiency and selectivity by using a novel class of myoglobin-based biocatalysts. These methods are useful for the synthesis of a variety of organic compounds which contain one or more new carbon-carbon or carbon-heteroatom (N, S, or Si) bond. The methods can be applied for conducting these transformations in vitro (i.e., using the biocatalyst in isolated form) and in vivo (i.e., using the biocatalyst in a whole cell system).
Myoglobin-catalyzed olefination of aldehydes
Tyagi, Vikas,Fasan, Rudi
supporting information, p. 2512 - 2516 (2016/02/18)
The olefination of aldehydes constitutes a most valuable and widely adopted strategy for constructing carbon-carbon double bonds in organic chemistry. While various synthetic methods have been made available for this purpose, no biocatalysts are known to mediate this transformation. Reported herein is that engineered myoglobin variants can catalyze the olefination of aldehydes in the presence of α-diazoesters with high catalytic efficiency (up to 4,900 turnovers) and excellent Ediastereoselectivity (92-99.9 % de). This transformation could be applied to the olefination of a variety of substituted benzaldehydes and heteroaromatic aldehydes, also in combination with different alkyl α-diazoacetate reagents. This work provides a first example of biocatalytic aldehyde olefination and extends the spectrum of synthetically valuable chemical transformations accessible using metalloprotein-based catalysts.
Using non-covalent interactions to direct regioselective 2+2 photocycloaddition within a macrocyclic cavitand
Nguyen, Nga,Clements, Aspen Rae,Pattabiraman, Mahesh
, p. 2433 - 2443 (2016/03/19)
The relative orientation of guests within ternary inclusion complexes is governed by the host-guest and guest-guest supramolecular interactions. Selectivity in 2+2 photocycloaddition between two alkenes included within a macrocyclic cavitand (γ-cyclodextrin) can be controlled using non-covalent interactions. In this manuscript, we report cavitand-mediated control of regioselectivity between alkyl cinnamates using non-covalent interactions. Using this method, we have shown that regioselectivity can be switched completely from a head-to-head dimer to a head-to-tail dimer. The reactions were also stereoselective in most cases. Stoichiometry experiments were performed to explore relative stabilities of the complexes, which indicate that the ternary complex is more stable than others. Selectivity in the photocycloaddition reaction was also applied retrospectively to deduce intermolecular orientations. Time-dependent conversion study we performed indicates that the observed reactivity of alkenes is representative of the intermolecular orientations in the bulk of the complex medium. Experimental observations and computational studies were used to qualitatively understand the complex structures, and relative magnitudes of the weak interactions. The reactions of complexes were studied in slurry form, and the extent of reaction control suggests a solid-state-like behavior.
Chemistry of Silylketenes: a Simple Preparation of α-Silyl-α-stannylacetic Esters and Their Stereoselective Reformatsky-type Reaction with Aldehydes or Aldimines
Akai, Shuji,Tsuzuki, Yasunori,Matsuda, Satoshi,Kitagaki, Shinji,Kita, Yasuyuki
, p. 2813 - 2820 (2007/10/02)
Silylketenes 1a, b reacted smoothly with alkoxystannanes 3 to give the corresponding α-silyl-α-stannylacetates 4 almost quantitatively.Treatment of 4 with TiCl4 caused selective cleavage of the C-Sn bond to bring about Reformatsky-type reaction with aldehydes 6 giving β-hydroxy-α-silyl esters 7.These two steps were carried out by one-pot operation, and variously substituted compounds 7 were obtained with high syn-selectivity (52-96percent d.e.) in 41-89percent yields.A similar one-pot procedure starting from 1a-c, 3, and aldimines 11 also provided the corresponding β-amino-α-silyl esters 12 with excellent syn-selectivity (96percent d.e. ) in 64-94percent yields.Stereocontrolled preparation of both (E)- and (Z)-α,β-unsaturated esters 8 and a syn-amino diol derivative 17 from syn-7 and syn-12, respectively, is also described.
