100862-95-1Relevant academic research and scientific papers
Exploration of the diastereoselectivity in an unusual Grignard reaction and its application towards the synthesis of styryl lactones 7-: Epi -(+)-goniodiol and 8- epi -(-)-goniodiol
Chavan, Subhash P.,Khatod, Harshali S.,Das, Tamal,Vanka, Kumar
, p. 50721 - 50725 (2016)
An unusual diastereoselective Grignard reaction is explored, where the Grignard reagents are derived from 1,n-dihaloalkanes. A steric bias due to the presence of a quaternary centre adjacent to the acetonide ester at the benzylic position is responsible for the formation of an intramolecularly reduced product in almost quantitative yield. This steric hindrance is responsible for the diastereoselectivity observed with a variety of aromatic as well as aliphatic esters. The unusual Grignard reaction furnishes long chain secondary alcohols possessing a terminal olefin, which are synthetically important intermediates. As an application of this method, the diastereoselective synthesis of styryl lactones viz. 7-epi-(+)-goniodiol (29) and 8-epi-(-)-goniodiol (30) has been achieved.
Tertiary alkylations of aldehydes, ketones or imines using benzylic organoboronates and a base catalyst
Nagao, Kazunori,Nakamura, Kei,Ohmiya, Hirohisa,Sato, Yukiya,Yabushita, Kenya
supporting information, p. 1065 - 1069 (2020/11/09)
The KHMDS-catalyzed tertiary alkylation of aldehydes, ketones or imines using tertiary benzylic organoboronates is reported. This protocol permitted the use of tertiary benzylic alkylboronates as the tertiary alkyl anion for construction of highly congested contiguous sp3 carbon centers. The mild and transition-metal-free reaction conditions are attractive features of the protocol.
DTBB-Catalysed dilithiation of styrene and its methyl-derivatives: Introduction of two electrophilic reagents
Yus, Miguel,Martínez, Pedro,Guijarro, David
, p. 10119 - 10124 (2007/10/03)
The reaction of styrene and some methyl-substituted styrenes 1 with lithium and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB) in the presence of several electrophiles [Me3SiCl, Me2CO, Et2CO, (CH2)5CO, Pr2CO], in THF, at temperatures ranging from -78 to 0°C, gave, after hydrolysis, products 2 resulting from addition of lithium to the olefinic double bond and successive trapping with the electrophilic reagent. When a carbonyl compound was used as electrophile, mixtures of the monoaddition-reduction compounds 3 and 4 were obtained as by-products, which could be easily separated from the diaddition products 2.
Generation of allylic and benzylic organolithium reagents from the corresponding ester, amide, carbonate, carbamate and urea derivatives
Alonso, Emma,Guijarro, David,Martinez, Pedro,Ramon, Diego J.,Yus, Miguel
, p. 11027 - 11038 (2007/10/03)
The reaction of different allylic and benzylic non-enolisable esters or amides (1), carbonates (4), carbamates (6, 7) and ureas (8) with an excess of lithium powder and a catalytic amount of naphthalene (10%) in the presence of an electrophile [(i)PrCHO, (t)BuCHO, PhCHO, Me2CO, Et2CO, (CH2)5CO, Ph2CO, Me3SiCl] in THF at different temperatures (-78, -30 or 0°C) leads, after hydrolysis with water to the corresponding allylated or benzylated products (2).
