FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2084497730> ?p ?o ?g. }

• W2084497730 endingPage "4458" @default.
• W2084497730 startingPage "4439" @default.
• W2084497730 abstract "Transition state modelling of the aldol reaction of Z enol borinates with chiral α-methyl aldehydes (see Schemes 4 and 6) suggests that three transition structures (F, AF, R) play a dominant role in controlling π-facial selectivity. The “Felkin” structure (F) is characterized by Me-CH---C(O)-C* and CH---C(O)-C*-Me dihedral angles of about −60°/−65° and +100°. The “Roush” structure (R) has values of −60°/−65° and ±175°/180°, while the “Anti-Felkin” one (AF) has values of +60°/+65° and about +50°. Our analysis suggests that nonbonded interactions play the most important role in determining aldehyde diastereofacial selectivity in the reactions with Z enolates, and that stereoelectronic effects are possibly overriden by steric effects. Reactions with aldehydes bearing relatively small and “flat” substituents (Ph-, H2CCH-, Me2CCH-) are 3,4-syn selective (“Felkin” selective) while reactions with aldehydes bearing bulkier groups (various alkyls) are 3,4-anti selective (“Anti-Felkin” selective) (see Tables 1 and 2). This result is essentially due to destabilization of both (F) and (R) structures. In particular, in order to relieve strain-energy structure (F) opens the CH---C(O)-C*-Me dihedral angle from +60° to ca. +100°. In this way the bulky substituents (alkyls) are pushed towards the aldehyde hydrogen. In the (AF) structure the CH---C(O)-C*-Me dihedral angle is around +50° and the [aldehyde hydrogen - alkyl] interaction disappears. Enolate aggregation and chelation effects in the case of lithium enolates can possibly explain discrepancies observed between lithium and boron enolates and between the experimental ratios and the force field-predicted ratios." @default.
• W2084497730 created "2016-06-24" @default.
• W2084497730 creator A5016051848 @default.
• W2084497730 creator A5019442123 @default.
• W2084497730 creator A5066984495 @default.
• W2084497730 creator A5072319898 @default.
• W2084497730 creator A5086984299 @default.
• W2084497730 creator A5090923610 @default.
• W2084497730 date "1992-01-01" @default.
• W2084497730 modified "2023-10-09" @default.
• W2084497730 title "Diastereofacial selectivity in the aldol reactions of chiral α-methyl aldehydes: a computer modelling approach." @default.
• W2084497730 cites W1508571065 @default.
• W2084497730 cites W1519204726 @default.
• W2084497730 cites W1545381187 @default.
• W2084497730 cites W1964571290 @default.
• W2084497730 cites W1969301843 @default.
• W2084497730 cites W1972355683 @default.
• W2084497730 cites W1986204385 @default.
• W2084497730 cites W1988385549 @default.
• W2084497730 cites W1991787162 @default.
• W2084497730 cites W1994781879 @default.
• W2084497730 cites W1998590511 @default.
• W2084497730 cites W1999901457 @default.
• W2084497730 cites W2000694159 @default.
• W2084497730 cites W2001078857 @default.
• W2084497730 cites W2008929482 @default.
• W2084497730 cites W2009828525 @default.
• W2084497730 cites W2027289511 @default.
• W2084497730 cites W2028856270 @default.
• W2084497730 cites W2032351529 @default.
• W2084497730 cites W2039503088 @default.
• W2084497730 cites W2049426867 @default.
• W2084497730 cites W2051015112 @default.
• W2084497730 cites W2053333781 @default.
• W2084497730 cites W2053405457 @default.
• W2084497730 cites W2060390716 @default.
• W2084497730 cites W2066224698 @default.
• W2084497730 cites W2073889820 @default.
• W2084497730 cites W2075319868 @default.
• W2084497730 cites W2077784436 @default.
• W2084497730 cites W2078671387 @default.
• W2084497730 cites W2078955945 @default.
• W2084497730 cites W2084913667 @default.
• W2084497730 cites W2088839054 @default.
• W2084497730 cites W2089526089 @default.
• W2084497730 cites W2089864383 @default.
• W2084497730 cites W2104834142 @default.
• W2084497730 cites W2131124255 @default.
• W2084497730 cites W2132732379 @default.
• W2084497730 cites W2143954925 @default.
• W2084497730 cites W2166010077 @default.
• W2084497730 cites W2316097434 @default.
• W2084497730 cites W2328341611 @default.
• W2084497730 cites W2328540233 @default.
• W2084497730 cites W2749779142 @default.
• W2084497730 cites W2949578284 @default.
• W2084497730 cites W2949840948 @default.
• W2084497730 cites W2950604837 @default.
• W2084497730 cites W2950992898 @default.
• W2084497730 cites W2952543383 @default.
• W2084497730 cites W2952683588 @default.
• W2084497730 cites W3005276043 @default.
• W2084497730 cites W3005433948 @default.
• W2084497730 doi "https://doi.org/10.1016/s0040-4020(01)80452-x" @default.
• W2084497730 hasPublicationYear "1992" @default.
• W2084497730 type Work @default.
• W2084497730 sameAs 2084497730 @default.
• W2084497730 citedByCount "50" @default.
• W2084497730 countsByYear W20844977302013 @default.
• W2084497730 countsByYear W20844977302014 @default.
• W2084497730 countsByYear W20844977302016 @default.
• W2084497730 countsByYear W20844977302020 @default.
• W2084497730 crossrefType "journal-article" @default.
• W2084497730 hasAuthorship W2084497730A5016051848 @default.
• W2084497730 hasAuthorship W2084497730A5019442123 @default.
• W2084497730 hasAuthorship W2084497730A5066984495 @default.
• W2084497730 hasAuthorship W2084497730A5072319898 @default.
• W2084497730 hasAuthorship W2084497730A5086984299 @default.
• W2084497730 hasAuthorship W2084497730A5090923610 @default.
• W2084497730 hasConcept C112887158 @default.
• W2084497730 hasConcept C118792377 @default.
• W2084497730 hasConcept C155647269 @default.
• W2084497730 hasConcept C161790260 @default.
• W2084497730 hasConcept C178790620 @default.
• W2084497730 hasConcept C185592680 @default.
• W2084497730 hasConcept C18616679 @default.
• W2084497730 hasConcept C201194858 @default.
• W2084497730 hasConcept C2779825165 @default.
• W2084497730 hasConcept C32909587 @default.
• W2084497730 hasConcept C61156836 @default.
• W2084497730 hasConcept C71240020 @default.
• W2084497730 hasConcept C89025888 @default.
• W2084497730 hasConcept C89031862 @default.
• W2084497730 hasConceptScore W2084497730C112887158 @default.
• W2084497730 hasConceptScore W2084497730C118792377 @default.
• W2084497730 hasConceptScore W2084497730C155647269 @default.
• W2084497730 hasConceptScore W2084497730C161790260 @default.
• W2084497730 hasConceptScore W2084497730C178790620 @default.

• next