Booker-Milburn

Lloyd-Jones, Booker-Milburn and coworkers described a novel Pdn-catalyzed di-amination of 1,3-butadienes as 6/1-384 with ureas 6/1-383 to give 6/1-385 (Scheme 6/1.97) [181]. The best results were obtained in the presence of p-benzoquinone, whereas with Cu-salts the turnover was inhibited. 

Booker-Milburn KI (1992) Synlett 809 Booker-Milburn KI, Thompson DF (1993) ibid 592... 

Catalyst conditions very similar to those employed in Eq. 42 and Scheme 12 were used recently by Lloyd-Jones, Booker-Milburn, and coworkers to achieve Pd-catalyzed diamination of conjugated dienes with urea nucleophiles (Eq. 44) [181], Both dioxygen and BQ were evaluated as oxidants, and BQ proved to be significantly more effective (Eq. 44). The beneficial effect of BQ probably arises from its ability to promote nucleophihc attack on the intermediate Tt-allyl palladiiun complex (see below. Sect. 4.4). This hypothesis is supported by the observation that the oxidative amination of styrene with urea, which does not undergo the second nucleophilic attack, proceeds equally effectively with both O2 and BQ as the oxidant (Eq. 45). 

The sesquiterpene (+)-asteriscanolide 1 was first isolated from Asteriscus aquaticus L and characterized by San Feliciano in 1985.1 It has captured the attention of organic chemists mainly because of its uncommon bicyclo[6.3.0]undecane ring system bridged by a butyrolactone fragment. The only prior enantioselective synthesis of 1 has been described by Wender in 1988 featuring an Ni(0)-promoted [4 + 4]-cycloaddition.2 Booker-Milburn and co-workers described the sequential application of intramolecular [2 + 2]-photocycloaddition, Curtius rearrangement, and oxidative fragmentation to produce the 7-desmethyl derivative in 1997.3... 

Hook, B.D.A., Dohle, W., Hirst, P.R., Pickworth, M., Berry, M.B., and Booker-Milburn, K.I. (2005) A practical flow reactor for continuous organic photochemistry. Journal of Organic Chemistry, 70, 7558—7564. 

Giilten, S., Sharpe, A., Baker, J.R., and Booker-Milburn, K.I. (2007) Use of temporary tethers in the intramolecular [2 + 2] photocydoaddition reactions of tetrahydrophthalimide derivatives a new approach to complex tricydic lactones. Tetrahedron, 63, 3659-3671. 

K. Booker-Milburn. personal communication K. Booker-Milburn, Synlett. 809 (1992),... 

Booker-Milburn et al. used the oxidative ring-expansion/cycHzation strategy they previously developed as an efficient way to stereoselectively build the bicyclo [5.3.0] framework of terpene-based natural products. For example, reaction of substrate 258 with iron (in) nitrate in DMF led to the formation of keto-alcohol 260 in fair yield as a single diastereomer (Scheme 76) [214]. Reduction of the final radical coming from the cyclization of 259 by 1,4-cyclohexadiene was smooth and the overall reaction proceeded without protection of the tertiary alcohol, opening the way to the total synthesis of pogostol and kessane. 

Similar strategies were used by Booker-Milburn et al. in approaches toward the synthesis of dictyol C and a-eudesmol [215], and by Blake et al. in approaches toward the synthesis of ophiobolin F and fusicoccin A [216]. 

Booker-Milburn, K. I., Guly, D. J., Cox, B., Procopiou, P. A. Ritter-Type Reactions of N-Chlorosaccharin A Method for the Electrophilic... 

---