343351-47-3Relevant academic research and scientific papers
Continuous Flow Preparation of (Hetero)benzylic Lithiums via Iodine-Lithium Exchange Reaction under Barbier Conditions
Weidmann, Niels,Harenberg, Johannes H.,Knochel, Paul
, p. 5895 - 5899 (2020/08/12)
Herein we report the generation of benzylic lithiums via an iodine-lithium exchange reaction on benzylic iodides performed in continuous flow using tBuLi as the exchange reagent. The resulting benzylic lithium species are trapped in situ by carbonyl electrophiles under Barbier conditions, resulting in benzylic secondary and tertiary alcohols. This flow procedure further allows the generation of highly reactive heterobenzylic lithium compounds, which are difficult to generate under batch conditions. A general scale-up was possible without further optimization.
Enantioselective 1,2-Anionotropic Rearrangement of Acylsilane through a Bisguanidinium Silicate Ion Pair
Cao, Weidi,Tan, Davin,Lee, Richmond,Tan, Choon-Hong
, p. 1952 - 1955 (2018/02/17)
Highly enantioselective bisguanidinium-catalyzed tandem rearrangements of acylsilanes are reported. The acylsilanes were activated via an addition of fluoride on the silicon to form a penta-coordinate anionic silicate intermediate. The silicate then underwent alkyl or aryl group migration from the silicon atom to the neighboring carbonyl carbon atom (1,2-anionotropic rearrangement), followed by [1,2]-Brook rearrangement to provide the secondary alcohols in high yields with excellent enantioselectivities (up to 95% ee). The isolation of an α-silylcarbinol intermediate as well as DFT calculations revealed that the 1,2-anionotropic rearrangement occurred via a bisguanidinium silicate ion pair, which is the stereodetermining step. The chiral center formed is then retained without inversion through the subsequent [1,2]-Brook rearrangement. Crotyl acylsilanes were smoothly transformed into homoallylic linear crotyl alcohols with retention of E/Z geometry, and no branched alcohols were detected. This clearly suggested that the 1,2-anionotropic rearrangement occurred through a three-membered instead of a five-membered transition state.
A simple and inexpensive procedure for low valent copper mediated benzylation of aldehydes in wet medium
Dubey, Akhil Kr.,Goswami, Dibakar,Chattopadhyay, Angshuman
experimental part, p. 137 - 145 (2010/10/02)
An operationally simple, inexpensive and efficient procedure for benzylation of aldehydes in wet medium has been developed that was mediated with low valent copper, prepared in situ through spontaneous reduction of CuCl 2-2H2O with magnesium in situ. Notably, copper mediated benzylation of 3h took place with good syn selectivity that was opposite to that for the corresponding Grignard addition. Finally, homobenzyl alcohol 5a was elegantly transformed into a known protease inhibitor synthon I. ARKAT USA, Inc.
Syntheses of tolrestat analogues containing additional substituents in the ring and their evaluation as aldose reductase inhibitors. Identification of potent, orally active 2-fluoro derivatives
Wrobel,Millen,Sredy,Dietrich,Gorham,Malamas,Kelly,Bauman,Harrison,Jones,Guinosso,Sestanj
, p. 2504 - 2520 (2007/10/02)
A series of aldose reductase inhibitors were prepared which were analogues of the potent, orally active inhibitor tolrestat (1). These compounds (5, 7, 9, and 10) have an extra substituent on one of the unoccupied positions on the naphthalene ring of 1. P
